X=-12-6y

-4x+5y=-39

slove by the system of substitution

X = - 6y - 12

4x + 5y = - 39

4x + 5y = - 39

-4 (-6y - 12) + 5y = - 39

-4 (-6y) + 4 (12) + 5y = - 39

24y + 48 + 5y = - 39

29y + 48 = - 39

29y = - 87

y = - 3

x = - 6y - 12

x = - 6 (-3) - 12

x = 28 - 12

x = 6

(x, y) = (6, - 3)