Solve for r
r<-9
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10r<-100+10
Add 10 to both sides.
10r<-90
Add -100 and 10 to get -90.
r<\frac{-90}{10}
Divide both sides by 10. Since 10 is positive, the inequality direction remains the same.
r<-9
Divide -90 by 10 to get -9.
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