Question

System of equations

Answer 1

x = -2 and y = 6

Explanation:

-2(-5x-5y= -20)

= 10x + 10y = 40

(-10x -2y = 8) + (10x+10y=40)

= 8y = 48

y = 48/8

y = 6

-5x - 5(6) = -20

-5x -30 = -20

-5y = -20+30

y = 10/-5

y = -2

Answer 2

(- 2, 6 )

Explanation:

given the system of equations

- 10x - 2y = 8 → (1)

- 5x - 5y = - 20 → (2)

multiplying (2) by - 2 and adding the result to (1) will eliminate x

10x + 10y = 40 → (3)

add (1) and (3) term by term to eliminate x

(- 10x + 10x) + (- 2y + 10y) = 8 + 40

0 + 8y = 48

8y = 48 ( divide both sides by 8 )

y = 6

substitute y = 6 into either of the 2 original equations and solve for x

substituting into (2)

- 5x - 5(6) = - 20

- 5x - 30 = - 20 ( add 30 to both sides )

- 5x = 10 ( divide both sides by - 5 )

x = - 2

the solution is (- 2, 6 )