Solve for x
x=\frac{-x_{21}-3}{2}
Solve for x_21
x_{21}=-2x-3
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2x=-x_{21}-3
Subtract 3 from both sides.
\frac{2x}{2}=\frac{-x_{21}-3}{2}
Divide both sides by 2.
x=\frac{-x_{21}-3}{2}
Dividing by 2 undoes the multiplication by 2.
-x_{21}=2x+3
Swap sides so that all variable terms are on the left hand side.
\frac{-x_{21}}{-1}=\frac{2x+3}{-1}
Divide both sides by -1.
x_{21}=\frac{2x+3}{-1}
Dividing by -1 undoes the multiplication by -1.
x_{21}=-2x-3
Divide 2x+3 by -1.
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Limits
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