Question 308751: y= x-4
y= -x+2 how to solve by substition
Answer by rapaljer(4671)   (Show Source):
You can put this solution on YOUR website! Substitute one of the y's in place of the other one.
Instead of writing
y=-x+2
replace this y with x-4:
y=-x+2
x-4=-x+2
Add +x to each side:
x+x-4=-x+x+2
2x-4=2
Add +4 to each side:
2x-4+4=2+4
2x=6
Divide both sides by 2
x=3
Now, you can find y in either equation. Take the first one:
y=x-4
y=3-4
y=-1
Check by substituting both values into the other equation
y=-x+2
-1=-3+2 It checks!!
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Seminole State College of Florida
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