Answer: x=3 and y=−2
Step-by-step explanation:
x=−2y−1;4x−4y=20
Step: Solve x=−2y−1 for x:
Step: Substitute−2y−1 for x in 4x−4y=20:
4x−4y=20
4(−2y−1)−4y=20
−12y−4=20(Simplify both sides of the equation)
−12y−4+4=20+4(Add 4 to both sides)
−12y=24
−12y
−12
=
24
−12
(Divide both sides by -12)
y=−2
Step: Substitute−2 for y x=−2y−1:
x=−2y−1
x=(−2)(−2)−1
x=3(Simplify both sides of the equation)