how do you solve this by using elimination? x + 2y = -6 and 3x + 8y = -20

Question

solve this two by elimination process

Answer 1

Elimination method

x+2y = -6

Multiple to each side by 3.

3x+6y = -18 --------> (1)

3x+8y = -20 --------> (2)

To eliminate the x value subtract equation (2) from (1).

3x+6y = -18

3x+8y = -20

(-) (-)    (+)

_________

-2y = 2

Divide to each side by negitive 2.

-2y/-2 = 2/-2

⇒ y = -1

Substitute the y value in (1).

3x+6*-1 = -18

3x-6 = -18

Add 6 to each side.

3x+6+6 = -18+6

3x = -12

divide to each side by 3.

3x/3 = -12/3

⇒ x = -4

Solution x = -4,y = -1.