Solve for x
x=-7
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-40=100+20x
Subtract 1 from 21 to get 20.
100+20x=-40
Swap sides so that all variable terms are on the left hand side.
20x=-40-100
Subtract 100 from both sides.
20x=-140
Subtract 100 from -40 to get -140.
x=\frac{-140}{20}
Divide both sides by 20.
x=-7
Divide -140 by 20 to get -7.
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