Answer:
15) 30
16) 2
for 15 you plug the -4 into the variable (x)
so...
-4(-4)-4-2-5(-4)
you do multiplication first because of PEMDAS
so -4×-4=16 it is not negative because there 2 negatives so they cancel out
then -5×-4=20
then you get this:
16-4-2+20 which equals 30
then with 16 you do the same. you just put the number for y in the variable y and same with x
