SOLUTION: Can someone please show me the steps to solving the system x+y=20 and x-y=28, using the substitution method? Thank you!

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Question 369668: Can someone please show me the steps to solving the system x+y=20 and x-y=28, using the substitution method? Thank you!
Found 2 solutions by Fombitz, ewatrrr:
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
1.x%2By=20
2.x-y=28
From eq. 1,
x=20-y
Substitute into eq. 2,
%2820-y%29-y=28
20-2y=28
-2y=8
highlight%28y=-4%29
Then from eq. 1,
x-4=20
highlight%28x=24%29

Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!


Hi,

solving the system x+y=20 and x-y=28, using the 'substitution' method:

1) choose one of the equations to solve for one of the variables

x - y = 28

x = y + 28

2) 'substitute' these findings for x into the other equation x+y=20 

y + 28 + y =20 

solve for y

2y = -8

y = -4

Finding x

x = y + 28 = -4 + 28 = 24

ordered pair( 24,-4) is the point these lines have in common