Solve for x
x=\frac{20-13y}{9}
Solve for y
y=\frac{20-9x}{13}
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9x=20-13y
Subtract 13y from both sides.
\frac{9x}{9}=\frac{20-13y}{9}
Divide both sides by 9.
x=\frac{20-13y}{9}
Dividing by 9 undoes the multiplication by 9.
13y=20-9x
Subtract 9x from both sides.
\frac{13y}{13}=\frac{20-9x}{13}
Divide both sides by 13.
y=\frac{20-9x}{13}
Dividing by 13 undoes the multiplication by 13.
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