Question

Solve by elimination 5x+2y=-11 and 3x+2y=-9

Answer 1

`5x + 2y = - 11 - - - (a) \\ 3x + 2y = - 9 - - - (b) \\ (a) - (b) : \\ 2x + 0y = - 2 \\ x = - 1 \\ (3 * - 1) + 2y = - 9 \\ - 3 + 2y = - 9 \\ 2y = - 6 \\ y = - 3 \\ { \boxed{x = - 1}} \\ { \boxed{y = - 3}}`

Answer 2

(- 1, - 3 )

Explanation:

Given the 2 equations

5x + 2y = - 11 → (1)

3x + 2y = - 9 → (2)

Subtract (2) from (1) term by term to eliminate y

2x = - 2 ( divide both sides by - 2)

x = - 1

Substitute x = - 1 into either of the 2 equations and solve for y

Substituting into (1)

5(- 1) + 2y = - 11

- 5 + 2y = - 11 ( add 5 to both sides )

2y = - 6 ( divide both sides by 2 )

y = - 3

solution is (- 1, - 3 )