equations and elimination

Question

-4x-2y =12 and 4x+8y =24

Answer 1

Given equations -4x-2y = 12 --------> (1)

4x+8y = 24 --------> (2)

To eliminate the x value, add the equations (1) and (2).

-4x-2y = 12

4x+8y = 24

__________

6y = 36

Divide to each side by 6.

6y/6 = 36/6

⇒ y = 6

Substitute the y value in (1).

-4x-2*6 = 12

-4x-12 = 12

Add 12 to each side.

-4x-12+12 = 12+12

-4x = 24

Divide to each side by negitive 4.

-4x/-4 = 24/-4

⇒ x = -6

Solution x = -6, y = 6.