The fourth term of an arithmetic sequence is 20, and the 13th term is 65. Find the sum of the first 13 terms

Answers

Answer 1

Answer:

S₁₃ = 455

Step-by-step explanation:

the sum to n terms of an arithmetic is

[tex]S_{n}[/tex] = [tex]\frac{n}{2}[/tex] [ 2a₁ + (n - 1)d ]

where a₁ is the first term and d the common difference

We require to find both a₁ and d

The nth term of an arithmetic sequence is

[tex]a_{n}[/tex] = a₁ + (n - 1)d

given a₄ = 20 and a₁₃ = 65 , then

a₁ + 3d = 20 → (1)

a₁ + 12d = 65 → (2)

subtract (1) from (2) term by term to eliminate a₁

9d = 45 ( divide both sides by 9 )

d = 5

substitute d = 5 into (1) and solve for a₁

a₁ + 3(5) = 20

a₁ + 15 = 20 ( subtract 15 from both sides )

a₁ = 5

Then

S₁₃ = [tex]\frac{13}{2}[/tex] [ (2 × 5 ) + (12 × 5 ) }

     = 6.5 (10 + 60)

     = 6.5 × 70

     = 455


Related Questions

A city population which was initially 15,500 has been decreasing 3% a year. What will the population be after five years? Round your answer to the nearest whole number

Answers

Answer:

3% = .03 x 15,500 = 465 / yr

465/yr x 5yrs = 2325

15,500 - 2325 = 13,175

Step-by-step explanation:

Jahnay wants to estimate how many ducks there are in her local park.
One day she puts a non-harmful tag on 20 of the ducks in the park.
The next day she catches 27 ducks and notices that 3 of these have a tag on them.
Work out an estimate for the total number of ducks in her local park.

Answers

Answer:

44 aproximately

Step-by-step explanation:

She puts a tag on 20 of them, the next day she catches 27 and notices 3 of them have a tag so we substract 27-3=24 we add 24 to the initial number of ducks (20) and the result is 44

Step-by-step explanation:

27÷3×20=180

or

3/27=20/n =180

so the numbers of ducks in her local park is 180

Find the missing angle.

Answers

Answer:

? = 56

Step-by-step explanation:

I've attached my work

Hope it helps, let me know if you have questions !

Have a nice rest of your day :)

In a game, if you roll a 6 on a 6-sided number cube, you lose a turn. (a) What is the probability that you roll a 6? Explain your reasoning. (b) What is the probability that you either roll a 6 or do not roll a 6? Explain your reasoning. (c) What is the probability that you don't roll a 6? Explain your reasoning

Answers

A) 1/6 six sides on the dice. B) 1 or 6/6 as everything is either a six or something else C) 5/6. Six sided dice six only makes up one of these sides so there are 5 others. Hope this helped

The total cost of 4 sodas and 6 patties is $840. If a customer buys 5 sodas and 5 patties, the total cost is $800. What is the cost of 1 soda and 1 patty?​

Answers

Answer:

S = $76 and P = $236

Step-by-step explanation:

Let the sodas be S and the patties P. So

4S + 6P = 840  and 5S + 5P = 800

By substitution method we will have the solution

5S + 5P = 800

5S = 800 - 5P

S = 800 - 5P

          5

We'll sustitute S with this equation

4S + 6P = 840

[tex]4(\frac{800 - 5P}{5})[/tex] + 6P = 80

4(800 - 5P) + 6P(5) = 840

3200 - 20P + 30P = 840

-20P + 30P = 840 - 3200

10P = -2360

P = -2360

        10

P = -236

Since the cost of the patty can't be negative, P = $236

Now that we know the cost of the patty, we can calculate the cost of the soda

S = 800 - 5P

          5

S = 800 - 5(236)

             5

S = 800 - 1180

             5

S = -380

        5

S = -76

Here S can't be negative, so S = $76

What is an equation of the line that passes through the points (3,6) and (−3,4)?

Answers

Answer:

y = x/3 +5

Step-by-step explanation:

Step1 : finding the slope

m = [tex]\frac{y2-y1}{x2-x1}[/tex]

(3,6) and (−3,4)

m = [tex]\frac{4-6}{-3-3}[/tex]

m = 1/3

Solving for the equation

y-y1 = m(x-x1) , (3,6)

y-6 = 1/3(x-3)

y = x/3 -1 +6

y = x/3 +5

In a school of 900 pupils, 30% are boys and 40% of the boys wear glasses.
How many boys wear glasses?​

Answers

Answer:

180

Step-by-step explanation:

First, we have to find out how many boys are in the school:

900 * 0.30 = 270

Now, we know that there are 270 boys. Out of these boys we need to find out how many boys have glasses:

270 * 0.40 = 108

180 is our answer.

Lowest common multiple of 10 and 20

Answers

Answer:

The lowest common multiple of 10 and 20 is twenty, and the maximum common multiple is 10

          [tex]\rule{50}{1}\large\textsf{\textbf{\underline{Question:-}}}\rule{50}{1}[/tex]

         What is the lowest common multiple of 10 and 20?

           [tex]\rule{50}{1}\large\textsf{\textbf{\underline{Answer and how to solve:-}}}\rule{50}{1}[/tex]

           First let's list a few common multiples of 10 and 20:-

[tex]\Large\textsf{Multiples of 10: 10, 20, 30, 40, 50, 60, 70, 80, 90, 100...}}[/tex]

        Now, let's list some multiples of 20:-

 [tex]\Large\textit{Multiples of 20: 20, 40, 60, 80, 100, 120, 140, 160...}[/tex]

      Now let's find the Least common multiple (L.C.M.) of 10 and 20:-

[tex]\Large\textsc{The LCM is 20}[/tex]

Good luck with your studies.

            [tex]\rule{50}{1}\smile\smile\smile\smile\smile\smile\rule{50}{1}[/tex]

The table below represents what type of function?

A. Linear
B. Nonlinear
C. Linear and nonlinear
D. Neither linear nor nonlinear

PLEASEEE I NEED THE ANSWER RIGHT NOWW

Answers

Answer:

nonlinear because the second row isn't going up by the same number

One angle on a parallelogram measures 155 what are the measures of the other angle

Answers

Answer: 25, 90 ,90

Step-by-step explanation:

One angle on a paralel = 155
=> x+ y + z + 155 = 360
  x + y + z = 205    ; x + y ; y + z ; x + z = 180

x + y = 180
=> Z = 205 - 180
    Z = 25  Degree
x = y = 90 degree

Mark me as Brainliest pls ! Tysm !

Find the slope will give brainlest

Answers

Answer:

See below ~

Step-by-step explanation:

Problem 20

Slope (m) = -4 + 6 / 4 + 5m = 2/9

Problem 17

m = rise / runm = 3/1m = 3

Problem 19

m = 2 + 3 / 6 - 2m = 5/4

Answer:

Problem 20: [tex]\frac{2}{9}[/tex]

Problem 17: 3

Problem 19: [tex]\frac{5}{4}[/tex]

Step-by-step explanation:

The formula to find slope is [tex]\frac{y_{2}-y_{1} }{x_{2}-x_{1} }[/tex]. Plugging in the given values in each problem, we can solve.

-----------------------------------

Problem 20:

[tex]\frac{-4-(-6)}{4-(-5)}[/tex]

[tex]=\frac{2}{9}[/tex]

-----------------------------------

Problem 17:

[tex]\frac{5-2}{3-2}[/tex]

[tex]=\frac{3}{1} =3[/tex]

-----------------------------------

Problem 19:

[tex]\frac{2-(-3)}{6-2}[/tex]

[tex]=\frac{5}{4}[/tex]

hope this helps!

delete = bad moderator
A Honda fit drove 3,172 km
Find what the gas mileage was for the vehicle used on the trip. Give the details on how you found it by showing the numbers and calculations you performed. Hint: a Honda fit drives 13.5 km per liter.

Answers

Answer:

See below ~

Step-by-step explanation:

Let's take an example :

I'm driving a car Z for 1,750 km and it has consumed 70 L of fuel.

===============================================================

Formula for mileage :

Mileage = Distance / Fuel consumed

=============================================================

Solving :

⇒ Mileage = 1,750 km / 70 L

Mileage = 25 km/L

=============================================================

Understanding by this method :

We can solve for the mileage of a car if we know how much distance it has covered in unit time, and the amount of fuel it has consumed, we can calculate mileage.

What is the value of 5k2−6 when k = 9?

Answers

Answer:

84

Step-by-step explanation:

Plug in 9 for k.

5(9)(2) - 6

first: (9)(2) = 9 x 2 = 18

5(18) - 6

second: 5(18) = 5 x 18 = 90

last: 90 - 6 = ?

84

hope this helps

Solve for the value of t

Answers

Answer:

T = 12

Step-by-step explanation:

8t+1=97

We move all terms to the left:

8t+1-(97)=0

We add all the numbers together, and all the variables

8t-96=0

We move all terms containing t to the left, all other terms to the right

8t=96

t=96/8

t=12

How many papayas could Star Market buy at Farm B for the same amount of money it spent at Farm A? Enter the answer in the box.

Answers

Do the math it really isn’t hard brotha

Navya has 104 feet of craft wire that she uses to make earrings. If each pair of earring requires & foot of wire, how hiany pairs of earrings is Navya able to make?​

Answers

Answer:

14 pairs of earrings

Step-by-step explanation:

Question

Navya has 10 ¹/₂ feet of craft wire that she uses to make earrings.  If each pair of earring requires 3/4 foot of wire, how many pairs of earrings is Navya able to make.

Given:

Total wire = 10 ¹/₂ ftWire required to make 1 pair of earrings = 3/4 ft

To calculate the number of pairs of earrings Navya can make, divide the total amount of wire by the wire required to make 1 pair of earrings:

[tex]\begin{aligned}\implies \sf 10\frac{1}{2} \div \dfrac{3}{4} &= \sf \dfrac{21}{2} \div \dfrac{3}{4}\\ \\& = \sf \dfrac{21}{2} \times \dfrac{4}{3}\\ \\& = \sf \dfrac{21 \times 4}{2 \times 3}\\ \\& = \sf \dfrac{84}{6}\\ \\& = \sf 14 \end{aligned}[/tex]

Therefore, Navya can make 14 pairs of earrings.


A lender estimates that the closing costs on a $170,000 home loan will be $6,375.00. The actual closing costs were 4.0%of the loan amount. Determine if the closing costs were higher or
lower than the estimate and by what percent
higher by 0.25%
higher by 0.5%
lower by 0.25%
lower by 0.5%

Answers

Answer:

  (a) higher by 0.25%

Step-by-step explanation:

The error in the estimate is found by comparing the estimated rate to the actual rate.

__

The rate of estimated closing costs is ...

  (estimated cost)/(home cost) × 100% = 6375/170000×100% = 3.75%

The actual rate is 4.00%.

  actual - estimate = 4.00% -3.75% = 0.25%

The actual closing costs were higher than the estimate by 0.25%.

Perform the indicated operation and simplify your answer.

7/17+(-6/17)

Answers

On my calculator it says 1/17 but I’m not sure you can try that and if it isn’t the right answer then im not sure good luck tho

Answer:

1/17 or 0.059

Step-by-step explanation:

7/17 + (-6/17) = 7/17 - 6/17 = 7-6/17 = 1/17

Dana is attaching a shelf to a wall and needs the shelf to be parallel to the floor. How many degrees should the shelf be
relatve to the foor?

A) O degrees

B) 90 degrees

C) 45 degrees

D) 225 degrees

Answers

Answer:  0 degrees (choice A)

Explanation:

By definition, the floor is assumed to be level and that means the floor is at a 0 degree angle. The shelf must also have this same angle relative to the floor so we have the shelf and floor as parallel planes. For more info, check out the converse of the corresponding angles theorem.

At the mall, 6 shirts cost $57. Each shirt costs the same amount. At this rate, how much would it cost to buy 4 shirts?



PRETTY PLEASE HELP!!!!

Answers

57/6 = $9.50 per shirt


9.50 x 4 = $38


Answer: $38

Answer:

$38

Step-by-step explanation:

57 ÷ 6 = 9.5

9.5 x 4 = 38

hope this helps

have a good day

What’s the answer to this question

Answers

Your answer will be
2x^2-16x+31 !!
If you would like an explanation, let me know!

Step-by-step explanation:

[tex] = 2(x - 5) ^{2} + 4(x - 5) + 1[/tex]

Now for the first term use the formula :

[tex] {a}^{2} - 2ab + {b}^{2} [/tex]

[tex] = 2( {x}^{2} - 10x + 25) + 4(x - 5) + 1[/tex]

[tex] = 2 {x}^{2} - 20x + 50 + 4x - 20 + 1[/tex]

[tex] = 2 {x}^{2} - 20x + 4x + 50 - 20 + 1[/tex]

[tex] = 2 {x}^{2} - 16x + 31[/tex]

HELP!!
Find x. Round to the nearest tenth.

Answers

Answer:

31.9°

Step-by-step explanation:

Applying the Law of Sines,

A = 75°a = 22 cmB = x°b = 12 cm

⇒ sin75° / 22 = sin x° / 12

⇒ sin (45 + 30)° / 22 = sin x° / 12

⇒ (1/√2)(√3/2) + (1/√2)(1/2) / 22 = sin x° / 12

⇒ (1/√2)(√3 + 1 / 2) / 22 = sin x° / 12

⇒ 12 × (2.73/2.82) / 22 = sin x°

⇒ x = sin⁻¹ (0.529)

⇒ x = 31.9° (nearest tenth)

What is 1 percent of 510

Answers

Answer:  " 5.1 " .
____________

Step-by-step explanation:
____________

To find 1 percent (i.e. " 1% " )  of:  510 ;

Note:  1 %  = (1 /100) = (1 ÷ 100) ;

Note the following about "dividing by "100" ;

  We take the number:  "510" in our case;
  and move the decimal point "2 (two) places backward" .
We move it "backward" (instead of "forward") because we are "dividing" ;

and we are moving the decimal point "2 (two)" spaces backward; since we are dividing by "100" ; which has "2 (two) zeros" .
  So:   " (510.) ÷ 100 " ;
               

      Take:  " 510." ; and move the decimal point two (2) spaces backward:
                         5.10.
                             

    To get: " 5.10 " ;  which we can simplify as:
             →  " 5.1 " ; which is our answer.

Hope this is helpful to you!  Wishing you well!
____________

5.1 is the correct answer to your question

I’ll give Brainlylist to whoever gets this correct - Due today
Please and thank you


P.S there’s two boxes called Data set 1 and Data set 2

Answers

Answer:

Step-by-step explanation:

Mean: Add all the values and divide by the # of values

Median: The center of the values

Mode: The value that appears the most in the data set

Mean for data set 1: 86

Mean for data set 2: (85+89+71+85+86+91+92+96+87)/2= approximately 86.89

Median for data set 1: 72,75,78,80,88,90,95,98,98

We've sorted it from least to greatest, and the center is 88 because there is 4 values to the left of it, and 4 values to the right. It's at the very center.

Median for data set 2: 71,85,85,86,87,89,91,92,96

The center for this is 87 because it is again, at the absolute center/middle between the data.

Mode for data set 1: 98 because it appears 2 times, which is more often than other values

Mode for data set 2: 85 because it appears most often (2 times) in the data set

Hope this helps! :)

Find the value of the variable that results in congruent triangles

Answers

Answer:

  y = 5

Step-by-step explanation:

The triangles will be congruent when corresponding sides are congruent. __

We already have ...

  KL ≅ NP . . . = 15 mm

  JL ≅ MP . . . = 22 mm

So, we need ...

  JK ≅ MN

  4y +12 = 32 . . . . substitute given values

This will be the case when ...

  4y = 20 . . . . . subtract 12

  y = 5 . . . . . . . divide by 4

The value of y that makes the triangles congruent is 5.

7. If c 1 b, what is <2?
A. 90
B. Not enough information
C. 82
D. 98

Answers

Answer:

A. 90°

Step-by-step explanation:

A perpendicular on a straight line creates 2 right angles.

We know the value of a right angle is 90°.

Hence :

∠2 = 90°

The mean of a math test took by 50 students is 85%. Teo students got 10%

Answers

Answer:

88%

Step-by-step explanation:


What is the slope of the line passing through the points
ear Equations
(-2, - 8) and (-3, — 9)₂

Answers

[tex](\stackrel{x_1}{-2}~,~\stackrel{y_1}{-8})\qquad (\stackrel{x_2}{-3}~,~\stackrel{y_2}{-9}) \\\\\\ \stackrel{slope}{m}\implies \cfrac{\stackrel{rise} {\stackrel{y_2}{-9}-\stackrel{y1}{(-8)}}}{\underset{run} {\underset{x_2}{-3}-\underset{x_1}{(-2)}}} \implies \cfrac{-9 +8}{-3 +2}\implies \cfrac{-1}{-1}\implies 1[/tex]

Answer:

Step-by-step explanation:

(-9 + 8)/(-3 + 2)= -1/-1= 1

Alex jogs 5,000 meters twice a day. How many kilometers does Alex jog each day?

A) 0.01 kilometer

B) 0.1 kilometer

C) 1 kilometer

D) 10 kilometers

Answers

1 kilometer = 1000 meters

5000 meters / 1000 = 5 kilometers


5 kilometers x 2 times per day = 10 kilometers per day.


answer: D) 10 kilometers

Solve for TV and SV. Select BOTH correct answers.
tv=8
sv=8√2
tv=8√2
sv-8

Answers

Answer:

TV = 8 , SV = 8[tex]\sqrt{2}[/tex]

Step-by-step explanation:

given ST = TV , then

TV = 8

using Pythagoras' identity in the right triangle

SV² = ST² + TV² = 8² + 8² = 64 + 64 = 128 ( take square root of both sides )

SV = [tex]\sqrt{128}[/tex] = [tex]\sqrt{64(2)}[/tex] = [tex]\sqrt{64}[/tex] × [tex]\sqrt{2}[/tex] = 8[tex]\sqrt{2}[/tex]

Other Questions
Wich word is a synonm for the word faint? Which element of the romantic movement is present in this excerpt from the the solitary reaper by William Wordsworth What is the primary goal of a community relations department?. please help me. please solve What happens to Nell?A.She escapes.B.She becomes ill.C.She dies.D.She falls asleep Which of the following is a monomial?O A. 4xO B. 5x2 + 2x +33O c.ocO D. X-1 the price for bulk pretzels is $3 for 4 pounds. how many pounds of pretzels can you buy for a dollar? hi help me with my question i will mark u as brainliest Who also wanted to be like the U.S. and want independence? . 2.SE Reading for understanding 1. What was mysterious about the journey at the start? 2. What effect did the storm have on the men and the ship? 3. Explain the danger that the ship and the men faced in the third paragraph. 4. How did the conditions in the fjord compare with those in the open sea? 5. What have you learned about the relationship between Erik and his men? what does insufferable mean in the paragraphhat does insufferable mean in the paragraph Help now please !!!! PLEASE HELP !!! These box plots show daily low temperatures for a sample of days in two different towns. Which statement is the most appropriate comparison of the spreads? Town A 10 15 20 30 55 Town B 5 20 30 40 55 What is the volume of the can? SHOW WORK. TIME REMAINING55:06Hazing is not violence because all parties involved are voluntary.Please select the best answer from the choices provided.TF i need help with this question please Read the passage.The Shelburne Museum is a great place for familles to visit. Most museums have just one building, but this museum has 39! The museumIncludes houses, barns, a lighthouse, and even an old steamship. It has fun things to interest people of all ages. My mother liked looking atpaintings from the 1800s. I enjoyed running through the gardens. My dad thought the old stagecoaches were cool. And my grandpa liked thewooden circus figures. This is the best museum I've ever seen!Which sentence from the passage best explains why the Shelburne Museum is good for families?1. The Shelburne Museum is a great place for families to visit.2. It has fun things to interest people of all ages.3. My dad thought the old stagecoaches were cool.4. This is the best museum Ive ever seen! What is 5/8 -2/4In its simplest form A cylinder has radius 14 inches and height 12 inches. A cone has the same radius and height. Round Volume answers to the nearest hundredth. A) Find the volume of the cylinder. V= B) Find the volume of the cone. V=C) What fraction of the cylinder's volume is the cone's volume? Describe a selected aspect of present and past climate and the associated physical parameters (eg, temperature, precipitation, sea level) or chemical composition (e.g. ocean pH) of the atmosphere geosphere, hydrosphere or cryosphere, related to the severe weather phenomena you chose. Include changes over time.