Solve for r
r=80
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\frac{40}{0.5}=r
Divide both sides by 0.5.
\frac{400}{5}=r
Expand \frac{40}{0.5} by multiplying both numerator and the denominator by 10.
80=r
Divide 400 by 5 to get 80.
r=80
Swap sides so that all variable terms are on the left hand side.
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