Answer:
I want to say its (-1,5) but I'm not sure
X - the number of loads by land carriers,
y - the number of loads by air carriers;
The system of inequalities:
x + y ≤ 150
2,000 x + 1,250 y ≤ 180,000
(-4)^-3 =
-4^-3 = 
Basically in this situation there is no difference whether parenthesis are used or not.