Question

Solve the system of equations -2x-y=-5−2x−y=−5 and 3x-4y=-423x−4y=−42 by combining the equations.

this is for elimination so if you could also include the steps for it that would be great thanks.

Answer 1

y = 9 and x = -2

Step-by-step explanation:

equations given:

• -2x - y = -5

• 3x - 4y = -42

Before doing elimination, we need to make either x or y, similar.

( -2x - y = -5 ) * 4

-8x - 4y = - 20 ____equation 1 [ here i am making y similar ]

3x - 4y = -42 _____ equation 2

solving simultaneously:

-8x - 4y = - 20

(-) 3x + 4y = +42

--------------------------------------

-11x = 22

x =
`(-22)/(-11)`

x = -2

Find y:

3x - 4y = -42 [ replace -2 as x ]

3(-2) - 4y = -42

-6 - 4y = -42

-4y = -42 + 6

-4y = -36

y = 9