Solve for r
r=1
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-4+5r-r=0
Subtract r from both sides.
-4+4r=0
Combine 5r and -r to get 4r.
4r=4
Add 4 to both sides. Anything plus zero gives itself.
r=\frac{4}{4}
Divide both sides by 4.
r=1
Divide 4 by 4 to get 1.
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