Solve for x
x=4y-21
Solve for y
y=\frac{x+21}{4}
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-x=21-4y
Subtract 4y from both sides.
\frac{-x}{-1}=\frac{21-4y}{-1}
Divide both sides by -1.
x=\frac{21-4y}{-1}
Dividing by -1 undoes the multiplication by -1.
x=4y-21
Divide 21-4y by -1.
4y=21+x
Add x to both sides.
4y=x+21
The equation is in standard form.
\frac{4y}{4}=\frac{x+21}{4}
Divide both sides by 4.
y=\frac{x+21}{4}
Dividing by 4 undoes the multiplication by 4.
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Limits
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