how do I simplify 5/3 +9/-5?
To simplify 5/3 + -9/5 you have to first get a common denominator between the two fractions you are adding. To do so, you most find a common multiple between 5 and 3. The common multiple between the two would be 15. So now since you have a common denominator you must put the numerator (top #) into the terms of the new denominator like so:
5/3 = 25/15
-9/5 = -27/15
Now that you have the "common" fractions, you are able to add them together, like so:
25/15 + -27/15 = -2/15