Question

A variable needs to be eliminated to solve

the system of equations below. Choose the
correct first step.
-4x + y = -35
-2x - y = -7
Add to eliminate x.
Add to eliminate y.
Subtract to eliminate x.
Subtract to eliminate y.

Answer 1

(7, - 7 )

Explanation:

- 4x + y = - 35 → (1)

- 2x - y = - 7 → (2)

adding the 2 equations term by term will eliminate the y- term

(- 4x - 2x) + (y - y) = - 35 - 7

- 6x + 0 = - 42

- 6x = - 42 ( divide both sides by - 6 )

x = 7

substitute x = 7 into either of the 2 equations and solve for y

substituting into (1)

- 4(7) + y = - 35

- 28 + y = - 35 ( add 28 to both sides )

y = - 7

solution is (7, - 7 )