Answer:
(x ,y)= (1/3, -4/3)
Step-by-step explanation:
simplify
y = -4x
x + 2y + 1 = -4x
multiply both sides
4x + y = 0
5 x + 2y = -1
eliminate one variable
-8x - 2y = 0
5x + 2y = -1
divide
-3x = -1
x = 1/3
possible solution
y= -4/3
check the solution
(x, y) = (1/3, -4/3)
simplify
-4/3 = 1/3 + 2 x (-4/3) + 1 = -4 x 1/3
place in order
-4/3 = -4/3 = -4/3