Math 221
posted by Erica .
Math 221  Ms. Sue, Sunday, July 13, 2014 at 2:24pm
I've done several problems for you. Now it's your turn.
How do you think this problem should be solved?
Answer this Question I was thinking that I should multiply the numerators and denominators

as with most problems involving fractions, work first with the denominators. They cannot be added or subtracted unless they all have the same denominator.
5/12 + 7/9
The GCD(12,9) = 36. So, what you have is
15/36 + 28/36
Now all the "units" are the same. Just as you cannot add apples and oranges, you cannot add twelfths and ninths. But you can add a bunch of 36ths. Since 15+28=43, the final answer is just 43/36.
Or, if you must, 1 7/36