Posted by Kim on .
How do we rewrite 7/a  9/b so that both terms have the denominator ab?

Math 
Bosnian,
7 / a Multiply Numerator and Denominator by b
7 / a = 7 b / a b
9 / b Multiply Numerator and Denominator by a
9 / b = 9 a / a b
7 / a  9 / b = 7 b / a b  9 a / a b =
( 7 b  9 a ) / a b