Question 459168: Solve by substitution. Check your answer.
x = 2y
y = 2x + 3
Answer by algebrahouse.com(1659)   (Show Source):
You can put this solution on YOUR website! x = 2y
y = 2x + 3
y = 2(2y) + 3 {substituted 2y, in for x, into bottom equation}
y = 4y + 3 {multiplied 2 by 2y}
-3y = 3 {subtracted 4y from both sides}
y = -1 {divided both sides by -3}
x = 2y {top equation}
x = 2(-1) {substituted -1, in for y, into top equation}
x = -2 {multiplied}
x = -2 and y = -1
Check:
x = 2y
-2 = 2(-1) {substituted in}
-2 = -2 {checks in top equation}
y = 2x + 3
-1 = 2(-2) + 3 {substituted in}
-1 = -4 + 3 {multiplied 2 by -2}
-1 = -1 {checks in bottom equation}
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