Question

How do you solve the system using the elimination method for -4x+y=-12 and 4x+2y=6?

Answer 1

First add the two equations together to get `3y = -6`,
hence `y = -2`

Secondly, you can subtract twice the first equation from the second to get `12x = 30`, hence `x = 5/2`

Explanation:

Add the two equations together to get:

`-6 = -12 + 6 = (-4x+y) + (4x+2y) = 3y`

Divide both ends by `3` to get `y = -2`

Subtract twice the first equation from the second to get:

`30 = 6 - 2(-12) = (4x+2y) - 2(-4x+y) = 12x`

Divide both ends by `12` to get `x = 30/12 = 5/2`