solve log7(x+9)-log7(10)​

Answer:

Step-by-step explanation:

According to the first statement, "Three years ago, Dedrick's age was a third of Francisca's age":

D - 3 = (1/3) * (F - 3)

According to the second statement, "In 13 years, Francisca's age will be twice Dedrick's age":

F + 13 = 2 * (D + 13)

Now, we have a system of two equations. We can solve these equations to find their current ages.

Step 1: Solve the first equation for D in terms of F:

D - 3 = (1/3) * (F - 3)

3D - 9 = F - 3

3D = F + 6

D = (F + 6) / 3

Step 2: Substitute the expression for D into the second equation:

F + 13 = 2 * ((F + 6) / 3 + 13)

Step 3: Solve for F:

F + 13 = 2 * ((F + 6) / 3 + 13)

F + 13 = 2 * (F + 6 + 39)

F + 13 = 2 * (F + 45)

F + 13 = 2F + 90

F - 2F = 90 - 13

-F = 77

F = -77

Step 4: Find D using the expression we found earlier:

D = (F + 6) / 3

D = (-77 + 6) / 3

D = -71 / 3

Now, we have found their ages, but we encounter a problem. Both Francisca and Dedrick's ages are coming out as negative, which is not meaningful in this context. It suggests that there might be an error in the initial information provided or in the equations derived from it.

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Functions which are polynomials are y=[tex]5x^{4} +x^{2} -8[/tex] ,y=[tex]7x^{3}[/tex] and y=[tex]6^{x}[/tex]

Given Functions : 1) y=[tex]-x^{2} +1/1-2x[/tex] 2)y=[tex]5x^{4} +x^{2} -8[/tex]. 3) y=[tex]7x^{3}[/tex]and g(x)=[tex]6^{x}[/tex].

We need to find which functions are polynomials. We know that polynomials is an expression consisting of indeterminates and coefficients that involves only the operations of addition, subtraction, multiplication and non negative integers .

First function is y=[tex]-x^{2} +1/1-2x[/tex]

The above function is not a polynomial because it has not a variable containing power in whole number and it is in fraction form. Two different polynomials can form numerator and denominator in a fraction.

Second function is y=[tex]5x^{4} +x^{2} -8[/tex]

The above function is a polynomial as it has a variable having power and it is not in fraction also.

Third function is  y=[tex]7x^{3}[/tex]

The above function is also a polynomial for the same reason.

Fourth function is g(x)=[tex]6^{x}[/tex].

The above function is also a polynomial.

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Answer:

5

Step-by-step explanation:

Given expression:

[tex]\dfrac{6^{n+2}-6^n}{6^{n+1}+6^n}[/tex]

[tex]\textsf{Apply exponent rule} \quad a^{b+c}=a^b \cdot a^c[/tex]

[tex]\implies \dfrac{6^n6^2-6^n}{6^n6^1+6^n}[/tex]

Factor:

[tex]\implies \dfrac{6^n(6^2-1)}{6^n(6^1+1)}[/tex]

Cancel [tex]6^n[/tex] :

[tex]\implies \dfrac{(6^2-1)}{(6^1+1)}[/tex]

Simplify:

[tex]\implies \dfrac{36-1}{6+1}[/tex]

[tex]\implies \dfrac{35}{7}[/tex]

[tex]\implies 5[/tex]

Answer:

155°

Step-by-step explanation:

z = 65° + y

y is a right angle

=> y = 90°

=> z = 65° + 90° = 155°

If a radioactive substance remains 80% of the initial amount then the half life of the radioactive substance is 2.5 years.

Given 80% of the initial amount of a radioactive substance remains.

If after 1 year the value or weight of the radioactive substance remains 80% means the rate of disappearing is 20% per annum.

If we clearly observe then it is forming a geometric progression and the rate is 80%.

Geometric progression will be if we assume the initial quantity be 100

is:

100,80,64,.........

we have to calculate the value of years in the value of term is 0.

the value of nth term of a geometric progression is [tex]ar^{n-1}[/tex]

so,

r is 0.8

100*[tex]0.8^{n-1}[/tex]=0

[tex]0.8^{n-1}[/tex]=0

if we calculate this we will find n-1=11

n=12

So the full life of radioactive substance is 12 and the half life will be 6 years.

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The volume of the air space surrounding the cone inside the cylinder is 1055.04 cm³

The volume of the air space surrounding the cone inside the cylinder is as follows:

volume of the air space = volume of cylinder - volume of a cone

volume of cylinder = πr²h

volume of cylinder = π16 × 5²

volume of cylinder = 400π

volume of the cone = 1 / 3 πr²h

volume of the cone = 1 / 3 × π × 12 × 4²

volume of the cone = 64π

Therefore,

volume of the air space = 400π - 64π

volume of the air space = 336π

volume of the air space = 1055.04 cm³

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The law of cosine helps us to know the third side of a triangle when two sides of the triangle are already known. The value of x is 117.8°. thus, the correct option is A.

The law of cosine helps us to know the third side of a triangle when two sides of the triangle are already known the angle opposite to the third side is given. It is given by the formula,

[tex]Cos(\theta) = \dfrac{a^2+b^2-c^2}{2ab}[/tex]

where

c is the third side of the triangle

a and b are the other two sides of the triangle,

and θ is the angle opposite to the third side, therefore, opposite to side c.

As per the law of cosine, the measure of angle x can be written as,

[tex]Cos(x) = \dfrac{12^2+5^2-15^2}{2(5)(12)}\\\\Cos(x) = \dfrac{-56}{120}\\\\x = 117.8^o[/tex]

Hence, the value of x is 117.8°. thus, the correct option is A.

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Answer:

35+3I

Step-by-step explanation:

35+3I

Answer:

a=75

b=70

c=110

d=105

e=110

f=105

Step-by-step explanation:

Answer: [tex]\left(\frac{4}{3}, -\frac{5}{3} \right)[/tex]

Step-by-step explanation:

Setting the equations equal to each other.

[tex]x-3=-2x+1\\\\3x=4\\\\x=\frac{4}{3}\\\\\implies y=\frac{4}{3}-3=-\frac{5}{3}[/tex]

The system of equation can be used to find the root of the equation is y= x³-4x² +2x and y=0 , y=4x² and y= x³+2x

An equation is a mathematical statement that is made up of two expressions connected by an equal sign.

y=-4x²

y= x³+2x

By equating the above equation we have

-4x²=x³+2x

Now, y= x³-4x² +2x

and y=0

By equating the above equation we have

x³-4x² +2x=0

y=4x²

y= -x³-2x

By equating the above equation we have

4x²=-x³-2x

Lastly,

y=4x²

y= x³+2x

By equating the above equation we have

4x²=x³+2x

Hence, the equation can be used is y= x³-4x² +2x and y=0 ,

y=4x² and y= x³+2x

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Answer:

x=67.4

Step-by-step explanation:

well sin30:1/2

So y is not 30 since 5/13 doesn’t equal 1/2

So it’s either the the third or fourth option

And x>y

So option 4 is correct

Answer:

(x+6)(y+3)

Step-by-step explanation:

Answer:

[tex]\fbox {Perimeter = 37.92}[/tex]

Step-by-step explanation:

Finding the missing side :

⇒ Take the tan value of the listed angle

⇒ tan 60° = √3 = 6/x

⇒ x = 6/√3 × √3/√3 = 2√3 = 2(1.73) = 3.46

Solving :

⇒ Perimeter = 10 + 2(6 + 3.46)

⇒ Perimeter = 10 + 2(9.46)

⇒ Perimeter = 19 + 18.92

⇒ Perimeter = 37.92

Answer: See Attachment

Step-by-step explanation: I wasn’t sure if you meant -2 < x, but that’s the work I did to get the answer. If you can, send a picture of the question itself in case you didn’t mean -2 < x.

Answer:

x² + 4x - 21 = 0

x² + 7x - 3x - 21 = 0

x ( x + 7 ) -3 ( x + 7 ) = 0

( x - 3 ) ( x + 7 ) = 0

∴ x - 3 = 0              or              x + 7 = 0

  x = 0 + 3                               x = 0 - 7

  x = 3                                      x = -7

Answer:

20

Step-by-step explanation:

the inverse of

y=1/2x + 10

is

x=1/2y+10

from here you just solve for y

x-10 = 1/2y

2(x-10) = y

2x-20 = y

The correct answer for the given expression is 99.22.

Expression in maths is defined as the collection of the numbers variables and functions by using signs like addition, subtraction, multiplication and division

The expression will be solved as:-

E = [tex]({5 -\dfrac{10}{27}})^3[/tex]

E = [tex](\dfrac{135-10}{27})^3[/tex]

E =[tex]\dfrac{125}{27}^3[/tex]

E = 99.22

Therefore the correct answer for the given expression is 99.22.

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Definition:

[tex]a^2=a\cdot a\\\\a^3=a\cdot a\cdot a\\\\a^4=a\cdot a\cdot a\cdot a\\\vdots\\a^n=\underbrace{a\cdot a\cdot a\cdot...\cdot a}_{n}[/tex]

also

[tex]a^1=a\\\\a^0=1[/tex]

[tex]6^1=6\\\\3^2=3\cdot3=9\\\\2^3=2\cdot2\cdot2=8\\\\1^7=1[/tex]

therefore

Answer: 484/5

Step-by-step explanation:

For this word problem, it seems confusing with the wording but the equation would just be:

968÷10=x

solving for x, we get 484/5.

The probability of getting at most one heads is 1/2

Let H represents Head and T represents Tail.

The sample space of two coin is:

S=(H,T),(T,T),(T,H),(H,H).

In the above sample, we have:

At most one head = 2

Total = 2

The required probability is then calculated as:

P = 2/4

Simplify

P = 1/2

Hence, the probability of getting at most one heads is 1/2

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The right step followed in the system to get he equations is (D). To get the system B. The second equation in system A was replaced by the sum of that equation and the first equation multiplied by 6. The solution to system B will be the same as the solution of system A.

A simultaneous equation can be defined as an equation that possesses two unknowns and one constant.

The solution to the problem can only be gotten by solving it side by side with another equation of the same format.

In conclusion, The right step followed in the system to get he equations is (D). To get the system B. The second equation in system A was replaced by the sum of that equation and the first equation multiplied by 6. The solution to system B will be the same as the solution of system A.

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Inequalities help us to compare two unequal expressions. The correct option is B.

Inequalities help us to compare two unequal expressions. Also, it helps us to compare the non-equal expressions so that an equation can be formed.

It is mostly denoted by the symbol <, >, ≤, and ≥.

For the given inequalities, the graph can be plotted as shown below. Now when the coordinates have been plotted the point that will satisfy both the inequalities is (-2,2).

Hence, the correct option is B.

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Answer:

3d²

Step-by-step explanation:

Hello!

To simplify, we combine the like terms by adding them.

Like terms are terms with the same variable and degree. A degree is a power to which the term is raised. Like terms can have numerical coefficients. For example, a coefficient of 4 to x² would mean 4 times x².

We can see that the variable d² is common throughout the three terms, meaning they are like terms. We can simply add and subtract them.

The simplified form is 3d².