So first you multiply the top (the numerator) by each other, then you multiply the bottom. Then you look at your answer and ask yourself “can I further simplify this?” In this case, you start by multiplying -7 by 3, which gives you -21. Then you multiply the bottom (9x5) which gives you 45. The answer (-21/45) is divisible by 3, so you divide the top and bottom by three to give you your simplest form, which is -7/15. Hope it helps!
