Solve for r
r=-5
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109=5-8r+64
Use the distributive property to multiply -8 by r-8.
109=69-8r
Add 5 and 64 to get 69.
69-8r=109
Swap sides so that all variable terms are on the left hand side.
-8r=109-69
Subtract 69 from both sides.
-8r=40
Subtract 69 from 109 to get 40.
r=\frac{40}{-8}
Divide both sides by -8.
r=-5
Divide 40 by -8 to get -5.
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