Question 171301: 2x-3y=-14
y=4x+8
solve this system of equations by substitution Found 2 solutions by gonzo, checkley77:Answer by gonzo(654) (Show Source):
You can put this solution on YOUR website! 2x - 3y = -14
y = 4x + 8
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since y = 4x + 8 in your second equation, you want to substitute 4x + 8 for y in your first equation.
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that equation is:
2x - 3y = -14
substituting 4x + 8 for y, it becomes:
2x - 3(4x + 8) = -14
simplify by removing parentheses:
2x - 12x - 24 = -14
add 24 to both sides of equation:
2x - 12x = 24 - 14
simplify:
-10x = 10
divide both sides by 10:
-x = 1
multiply both sides by -1
x = -1
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take your second equation and solve for y now that you know that x = -1:
y = 4x + 8
y = 4*(-1) + 8
y = -4 + 8
y = 4
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take your first equation and substitute -1 for x and 4 for y:
2x - 3y = -14
2*(-1) - 3*(4) = -14
-2 -12 = -14
-14 = -14
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values for x and y are good.
x = -1
y = 4
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You can put this solution on YOUR website! 2x-3y=-14
y=4x+8
2x-3(4x+8)=-14
2x-12x-24=-14
2x-12x-24+14=0
-10x-10=0
-10x=10
x=10/-10
x=-1 ans.
2*-1-3y=-14
-2-3y=-14
-3y=-14+2
-3y=-12
y=-12/-3
y=4 ans.
Proof:
4=4*-1+8
4=-4+8
4=4
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