Since a serving is 1/2 cup and he needs 72 servings you can multiply 72 by 1/2 and find out that he needs to make 36 cups of punch. Two cups is a pint so he needs (36 / 2) 18 pints of juice. He already has the 8 pints of pineapple juice so 18 - 8 leaves 10 pints of orange juice.
N=d-2
q=n+d =>q=(d-2)=q=2d-2
25q+5n+10d=525
replace q and n with d
25(2d-2) +5(d-2)+10d=525
50d-50+5d-10+10d=525
65d=585
d=9
n=7
q=16
Y = (x - 2)/3
3y = x - 2
x = 3y + 2
Therefore, the inverse of y = (x - 2)/3 is y = 3x + 2