Question

Write the expression as a single fraction and simplify.
3/a + 3/b

Is this when you cross multiply and get 3a + 3b? Except the answer has to be a fraction so I am not sure.

Answer 1

You did the right thing to get the numerator. Now just put it all over the common denominator:

(3a+3b) / ab

when you're solving equations, the cross-multiplying affects both sides of the equation. When just evaluating an expression, you need to remember <u>why</u> you are cross-multiplying. It's to put everything over the common denominator.

Answer 2

Thank you!!!