Question

I neeed to solve this equation with elimination

Answer 1

Answer:

The solution to the system of equations be:

• x = 3

• y = 9

Step-by-step explanation:

Given the system of equations

x + y = 12

-x + 2y = 15

Let us solve the system of equations by elimination

$\begin{bmatrix}x+y=12\\ -x+2y=15\end{bmatrix}$

adding the equations

$-x+2y=15$

$+$

$\underline{x+y=12}$

$3y=27$

solve 3y = 27 for y

$3y=27$

divide both sides by 3

$\frac{3y}{3}=\frac{27}{3}$

Simplify

$y=9$

For x+y=12 plug in y = 9

$x+9=12$

Subtract 9 from both sides

$x+9-9=12-9$

Simplify

$x=3$

Therefore, the solution to the system of equations be:

• x = 3

• y = 9