Solve for a
a=\frac{9}{r}
r\neq 0
Solve for r
r=\frac{9}{a}
a\neq 0
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\frac{1}{9}ar=1
Swap sides so that all variable terms are on the left hand side.
\frac{r}{9}a=1
The equation is in standard form.
\frac{9\times \frac{r}{9}a}{r}=\frac{9}{r}
Divide both sides by \frac{1}{9}r.
a=\frac{9}{r}
Dividing by \frac{1}{9}r undoes the multiplication by \frac{1}{9}r.
\frac{1}{9}ar=1
Swap sides so that all variable terms are on the left hand side.
\frac{a}{9}r=1
The equation is in standard form.
\frac{9\times \frac{a}{9}r}{a}=\frac{9}{a}
Divide both sides by \frac{1}{9}a.
r=\frac{9}{a}
Dividing by \frac{1}{9}a undoes the multiplication by \frac{1}{9}a.
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