Solve for a
a=4
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7\left(8+a\right)=12\left(a+3\right)
Variable a cannot be equal to -3 since division by zero is not defined. Multiply both sides of the equation by 7\left(a+3\right), the least common multiple of 3+a,7.
56+7a=12\left(a+3\right)
Use the distributive property to multiply 7 by 8+a.
56+7a=12a+36
Use the distributive property to multiply 12 by a+3.
56+7a-12a=36
Subtract 12a from both sides.
56-5a=36
Combine 7a and -12a to get -5a.
-5a=36-56
Subtract 56 from both sides.
-5a=-20
Subtract 56 from 36 to get -20.
a=\frac{-20}{-5}
Divide both sides by -5.
a=4
Divide -20 by -5 to get 4.
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