Use substitution to solve the following.

y = 4x

2y + 2.5x = 105

Answer:

[tex]x=-6; y=4[/tex]

Step-by-step explanation:

Step 0: retwite the second equation by dividing LHS and RHS by 3.

[tex]x+2y=2[/tex]

Step 1: combine them as the first minus twice the second to eliminate y

[tex]I - 2\times II : 5x+4y -2x-4y=-14-4 \rightarrow 3x=-18 \rightarrow x= -6[/tex]

Step 2a: At this point I would replace the value of x in the second equation to easily solve for y.  That will give you [tex]-6+2y=2 \rightarrow y=4[/tex]. I do imagine you're required to use the same method to solve for y even if it's slower so...

Step 2b: Combine them again, taking the first minus 5 times the second to eliminate x:

[tex]I-5II: 5x+4y-5x-10y=-14-10 \rightarrow -6y=-24 \rightarrow y=4[/tex]

Answer:

c

Step-by-step explanation:

right now 15 is the mode because there are 3 of them

if we made it so that there was another 8 there would also be 3 of them

this would mean that there are two modes

The surface area of the regular pyramid is 770 [tex]m^{2}[/tex]

Option B. 770  [tex]m^{2}[/tex] is the answer.

The surface area of a pyramid is a measure of the total area that is occupied by all its faces.

We have to find the surface area of the regular pyramid with a base of 6 sides (hexagonal base).

Surface area of pyramid = area of triangles at the lateral sides + area of base (Hexagon)

Surface area of hexagonal base,

[tex]\frac{1}{2}*(Apothem)*(Perimeter) \\= \frac{1}{2}*(6\sqrt{3} )*(72)\\=216\sqrt{3}[/tex]

Surface area of triangular sides = 6 * 1/2 * b *h

                                                       = 3 * 12 *11

                                                       = 396  [tex]m^{2}[/tex]

Now total surface area = 216√3 + 396

                                        = 374.112 + 396

                                        = 770.112

                                        ≈ 770 [tex]m^{2}[/tex]

The surface area of the regular pyramid is 770 [tex]m^{2}[/tex]

Option B.  770 [tex]m^{2}[/tex]

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The estimation of the fractions to the nearest whole number is [tex]5\frac{13}{40}[/tex]

The fractions are in mixed fractions. Let's convert it to improper fraction and do the arithmetic.

Therefore,

[tex]8\frac{1}{5} - 2\frac{7}{8}[/tex]

[tex]8\frac{1}{5}=\frac{41}{5}[/tex]

[tex]2\frac{7}{8} =\frac{23}{8}[/tex]

Therefore,

[tex]\frac{41}{5} -\frac{23}{8} = \frac{328-115}{40} =\frac{213}{40}[/tex]

Hence,

[tex]\frac{213}{40} =5\frac{13}{40}[/tex]

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The number of ways for which different sets of 10 comic books could you choose to buy will be 1.731 x 10¹³.

A permutation is an act of putting things or elements in the right sequence. Combinations are a method of picking things or pieces from a collection of objects or sets when the sequence of the objects is irrelevant.

There are 100 comic books to choose from at the local hobby store.

Then the number of ways for which different sets of 10 comic books could you choose to buy will be

Total ways = ¹⁰⁰C₁₀

Total ways = 1.731 x 10¹³

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Explanation:

Let B represent the unmarked angle on the left between angle A and the 145 degree angle.

Angle B and the 145 degree angle form a straight line of 180 degrees

B+145 = 180

B = 180-145

B = 35

Then use the fact that angles A and B form a 90 degree angle

A+B = 90

A+35 = 90

A = 90-35

A = 55

Answer:

A, C

Step-by-step explanation:

A  True   it IS a right triangle because   5^2 + 12 ^2 = 13^2

      and scalene  because the leg legths are not =

C   always true of triangles

Answer:

5/3

Step-by-step explanation:

Substitution

Answer:

5/3 or 1 2/3 (also, there is no graph so I had to do subsitution)

Step-by-step explanation:

If we substitute, we get 3 = 3x-2. We add 2 to both sides and get 5 = 3x

We divide 3 from both sides and get 5/3 = x or x = 5/3

Hope this helped! I would appreciate a Brainliest if this answer helped you! Thank you and have a good day!

Answer: have started giving out meals to the homeless "49"

Answer:

4.51352cm

Step-by-step explanation:

The factor of the given quadratic polynomial 9x² - 12x + 4 is (3x - 2) and (3x - 2).

It is a method for dividing a polynomial into pieces that will be multiplied together. At this moment, the polynomial's value will be zero.

The quadratic polynomial is given below.

9x² - 12x + 4

Then by the factorization, we have

9x² - 6x - 6x + 4

3x(3x - 2) - 2(3x - 2)

(3x - 2)(3x - 2)

(3x - 2)²

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Answer:

f(x) = x - 3

Step-by-step explanation:

note that y = f(x) , then

x - y = 3 ( add y to both sides )

x = 3 + y ( subtract 3 from both sides )

x - 3 = y , that is

f(x) = x - 3

f(x) = x - 3  is the equation written in function notation, with x as the independent variable.

A relationship between a group of inputs and one output is referred to as a function. In plain English, a function is an association between inputs in which each input is connected to precisely one output. A domain, codomain, or range exists for every function. Typically, f(x), where x is the input, is used to represent a function.

To write the equation x - y = 3 in function notation with x as the independent variable, we need to solve for y in terms of x.

x - y = 3

y = x - 3

Therefore, the function represented by the equation x - y = 3, with x as the independent variable, can be written in function notation as:

f(x) = x - 3

So the answer is O f(x) = x - 3.

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Answer:

5/8

Step-by-step explanation:

Answer: The answer is 5/8. Try reducing using 58

Answer:

7

Step-by-step explanation:

Because 9 can go into 63, 7 times.

Answer:

89.0857

Step-by-step explanation:

Hope this helps! Have a great day!!

Question:

please tell me what 16/7+86.8 is

Answer:

89.08571429

Simplified version:

89.08

Step-by-step explanation:

So you have the fraction:

16 over 7

And you have your whole number/decimal:

86.8

What you would do is:

So your broken down fraction should have the numbers in this specific order: 2.28571429

Add the two number together: (Add 2.28571429 and 86.8)

You would start at the end of your problem

9 + 0 = 9

2 + 0 = 2

4 + 0 = 4

1 + 0 = 1

7 + 0 = 7

5 + 0 = 5

8 + 0 = 8

2 + 8 = 10

2 + 86 = 88 + 1 (From the 10) = 89

So, to conclude, 16/7 + 86.8 = 89.08571429

Then, simplified it is: 89.08 or 89.0/89

If you need to simplify to only one digit after the decimal, the answer would be 89

If you are wondering why then the reason why you wouldn't add the .0 is because you never add the .0 at the end. If your answer is 89.08 then you cannot take away that 0 because you only take away the 0 if its at the end of your answer.

(Examples.)

X for Don't take away 0

[tex]\sqrt[/tex] for Take away 0

89.08 X

37.30 [tex]\sqrt[/tex]

12.6802 X

15.670 [tex]\sqrt[/tex]

16.05 X

15.50 [tex]\sqrt[/tex]

6.903 X

And so on.

Answer:

0.00043 in standard form is 0.00043

0.00043 in scientific notation is [tex]4.3*10^{-4}[/tex]

Step-by-step explanation:

or zero and forty three hundred thousandths

Answer:

[tex]0[/tex] (no change)

Step-by-step explanation:

Recall that the average rate of change of a function [tex]f(x)[/tex] over the interval [tex][a,b][/tex] is equal to [tex]\frac{f(b)-f(a)}{b-a}[/tex]:

[tex]\frac{h(b)-h(a)}{b-a}\\ \\\frac{h(6)-h(1)}{6-1}\\\\\frac{0-0}{5}\\ \\0[/tex]

Hence, the average rate of change of the function [tex]h(x)[/tex] over the interval [tex][1,6][/tex] is [tex]0[/tex], or no change.

Answer:

h = 28.5 ft

Step-by-step explanation:

the 2 situations are similar, that is the triangles formed in both cases are similar.

then the ratios of corresponding sides are in proportion

let h be the height of the house , then

[tex]\frac{4.7}{h}[/tex] = [tex]\frac{9.4}{57}[/tex] ( cross- multiply )

9.4h = 4.7 × 57 = 267.9 ( divide both sides by 9.4 )

h = 28.5 ft

Using proportions, it is found that they had traveled 624 miles when Christopher fell asleep.

A proportion is a fraction of a total amount, and the measures are related using a rule of three.

In this problem, Christopher fell asleep at a distance that is 65% of 960 miles, hence the distance they had traveled is given by:

D = 0.65 x 960 miles = 624 miles.

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Step-by-step explanation:

135+k=180(sum of angles on a straight line)

k=180-135

k=45

so now u can use k to solve for x

k+9x is also on a straight line

so k+9x=180

we know k so substitute the value in the equation

45+9x=180

9x=180-45

9x=135

[tex] \frac{9x}{9} = \frac{135}{9} [/tex]

cancel 9 will divide 135 15 times

therefore x=15 degrees

Answer:

Valentina got 4 times more hair cut off than her sister

Step-by-step explanation:

1 4 4

- × - = -

5 1 5

Valentina got 4 times more hair taken off than her sister, as the ratio between them is 4:1.

The ratio is the simplest form of a fraction involving two quantities determining each other. It is written as a:b, read as "a is to b", and functions as a/b.

In the question, we are informed that Valentina and her sister went together to get haircuts. Valentina got 4/5 of an inch cut off and her sister got 1/5 of an inch cut off.

We are asked to find a comparison between the two.

To find the comparison, we will find the ratio of the haircut Valentina got to that of what her sister got.

Therefore, ratio = (4/5):(1/5) = (4/5)/(1/5) = 4.

Therefore, Valentina got 4 times more hair taken off than her sister.

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Answer:

Distributive property

Step-by-step explanation:

The distributive property states that if you have an equation inside parenthesis with a number outside, you should multiply the number with each of the member inside the parenthesis. So lets say you have 3(1-4), you are not going to add the members together after multiplication, you are gonna apply the mathematical equation that was available in the first place, so u will multiply 3×1 - 3×4, this applies to any situation you have. Let’s say you have 3+(4-2), here you cannot multiply the 3 by any of the parenthesis, since there is an addition sign right before it, we conclude that the number should be right beside the parenthesis bcz parenthesis are like multiplication signs. So you have 3(4-2), first step you do is multiply each of the number inside by the number outside, and you will get the subtraction sign in the middle of them. It will look like this 3×4 -3×2, u multiply them all together, with the multiplication first and subtraction at last.

ur wlcm :)

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Answer:

1

Step-by-step explanation:

f(x)= -х² + 5

f(-2)= -2²+5

f(-2)= -4+5

f(-2)= 1