Question

IN DESPERATE NEED OF HELP :(

Answer 1

So, the problem is asking for one of the equations to be rewritten. Lets rewrite the second one. The way to create a system of equations that will cancel is to create a situation where the a or b of both equations add to 0. In this case, we can multiply the second equation by 3 to turn the 3y into 9y.

$3(-x + 3y) = (6)3$

$-3x + 9y = 18$

Our new system is $4x - 9y =9$ and $-3x + 9y = 18$. We can now add these together.

$4x - 9y = 9$

$-3x + 9y = 18$

Adding each part straight down, we get the equation:

$x + 0 = 27$

We now have an equation with a single variable, which also tells us that x is equal to 27.

Extra: To find the value of y after this, we merely need to plug in the value of x to one of the equations and solve for y.

$-27 + 3y = 6$

$3y = 33$

$y = 11$