SOLUTION: How do u do 1/5y=x+4 and y-x=8 in substitution and elimination

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Question 909672: How do u do 1/5y=x+4 and y-x=8 in substitution and elimination
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
1%2F5y = x + 4
and
y - x = 8
Arrange for substitution, add x to both sides
y = (x + 8)
Replace y in the 1st equation
1%2F5(x+8) = x + 4
multiply both sides by 5
x + 8 = 5(x + 4)
x + 8 = 5x + 20
8 - 20 = 5x - x
-12 = 4x
x = -12/4
x = -3
Find y
y = -3 + 8
y = 5
:
Elimination,
y - x = 8
1%2F5y - x = 4 (subtracted x from both sides)
----------subtraction eliminates x, find y
4%2F5y + 0 = 4
multiply both sides by 5
4y = 5(4)
divide both sides by 4
y = 5
:
You can find x here