Answer:
15w - 15y - 36
Explanation:
Combine like terms
In this case the only two terms would be numbers without variable and numbers with the variable w
First lets combine the numbers with no variable which are -16 and -20. you subtract these two -16 - 20 = -36 and get -36
Now lets combine like terms for w, it doesn't matter which order you go in exactly but in the case I will do
1. combine 8w and 7w, since these are both positive you will add the together
8w + 7w = 15w
2. Now combine -11y and -4y, since these are both negative you will subtract them and get -15y