Solve system of equations for x + y: -4x + 9y = -11 & -3x + 7y =-9
Thanks!!

Step-by-step explanation:

(- 4, - 3 )

Step-by-step explanation:

Given the 2 equations

- 4x + 9y = - 11 → (1)

- 3x + 7y = - 9 → (2)

Multiplying (1) by 3 and (2) by - 4 and adding will eliminate the term in x

- 12x + 27y = - 33 → (3)

12x - 28y = 36 → (4)

Add (3) and (4) term by term to eliminate x

- y = 3 ( multiply both sides by - 1 )

y = - 3

Substitute y = - 3 into either of the 2 equations and evaluate for x

Substituting into (1)

- 4x + 9(- 3) = - 11

- 4x - 27 = - 11 ( add 27 to both sides )

- 4x = 16 ( divide both sides by - 4 )

x = - 4

Solution is (- 4, - 3 )

72 is the answer to this problem