How do you solve #10/3=(r+6)/(r+9)#?

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Answer 1 · 2017-02-27T05:53:28

The solution is #r=-72/7# or #-10 2/7#.

Solve:

#10/3=(r+6)/(r+9)#

Cross multiply.

#10(r+9)=3(r+6)#

Expand.

#10r+90=3r+18#

Subtract #3r# from both sides.

#7r+90=18#

Subtract #90# from both sides.

#7r=-72#

Divide both sides by #7#.

#r=-72/7#

As a mixed fraction:

#r=-10 2/7#