52.5
Explanation:
x/18. 30/100 cross multiply 30*18=5250
5250 divided by 100= 52.5
9(2w−y)=21w−9y
First you multiply the numbers in the parenthesis by 9

subtract. 21w-18w=3w

add. -9y+9y=0

divide.

Final answer is 0.
F(x+h) = 2(x+h) +3= 2x + 2h +3
f(x) = 2x + 5
f(x+h) - f(x) = 2x + 2h + 3- 2x - 3= 2h
[f(x+h) - f(x)]/h = 2h/h = 2