Answer:
27
Step-by-step explanation:
Let <em>g </em>be Gabrielle's age and <em>m </em>be Mikhail's age.
We can turn the statements the problem gives us into mathematical expressions to help us solve.
Gabrielle's age is two times Mikhail's age:
<em>g </em>= 2<em>m</em>
The sum of their ages is 81:
<em>g </em>+ <em>m </em>= 81
This gives us a system of equations that will allow us to solve for Gabrielle's age.
<em>g </em>+ <em>m </em>= 81
(2<em>m</em>)<em> </em>+ <em>m </em>= 81
3<em>m </em>= 81
<em>m</em> = 
<em>m </em>= 27
If we need to solve for Gabrielle's age, we can do the following.
<em>g </em>= 2<em>m</em>
2(27)<em> </em>= <em>g</em>
54 = <em>g</em>
g = 54
Mikhail's age is 27.
Gabrielle's age is 54.
Using a system of equations, it is found that the third graph shows a pair of lines that represent the equations with a solution (−5, 2).
<h3>What is a system of equations?</h3>
A system of equations is when two or more variables are related, and equations are built to find the values of each variable.
The solution of the system on a graph is the intersection of two lines. The third graph has an intersection at (-5,2), hence it is the answer to this question.
More can be learned about a system of equations at brainly.com/question/24342899
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Answer:
$60
Step-by-step explanation:
12/8 = x/40
40(12/8) = x
60 = x
The blue ray and the tv combined is 490 so just divide by 2 there’s your answer bud
Answer:
4000 
Step-by-step explanation:
V = 1/3(Bh) where B is the area of the base and h is the height of the pyramid
B = 20(20) = 400 h = 30
V = 1/3(400)(30) = 4000 