Solve for x
x=-\frac{r}{2}+4
Solve for r
r=8-2x
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2x=8-r
Subtract r from both sides.
\frac{2x}{2}=\frac{8-r}{2}
Divide both sides by 2.
x=\frac{8-r}{2}
Dividing by 2 undoes the multiplication by 2.
x=-\frac{r}{2}+4
Divide 8-r by 2.
r=8-2x
Subtract 2x from both sides.
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