Answer:
(- 5, 9 )
Explanation:
y = - 2x - 1 → (1)
3x - 4y = - 51 → (2)
substitute y = - 2x - 1 into (2)
3x - 4(- 2x - 1) = - 51 ← distribute parenthesis on left side and simplify
3x + 8x + 4 = - 51
11x + 4 = - 51 ( subtract 4 from both sides )
11x = - 55 ( divide both sides by 11 )
x = - 5
substitute x = - 5 into (1)
y = - 2(- 5) - 1 = 10 - 1 = 9
solution is (- 5, 9 )