Answer: 
Step-by-step explanation:
Given
New mail carrier takes 4 hours for delivery i.e.
New mail carrier completes 
part of work in 1 hour
Old mail carrier takes 3 hours for delivery i.e.
mail carrier completes 
part of work in 1 hour
If they work together, they complete the work in x hours i.e.
top left
is not
Step-by-step explanation:
The two black circles represents "The selling prices that produces no profit." If the selling is 10, the profit is 0. If the selling price is 60, the profit is 0.
The selling price that provides the maximum profit is represented by the red dot. It is between the selling price of 30 and 40. Its maximum profit is equal to 12,000.
All you have to do is follow PEMDAS (if you don't know what that is, search it up).
-2-5(4n-6)=-132
Distribute the 5 to everything in the parentheses.
-2-20n+30= -132
Combine like terms.
-20n+28 = -132
Subtract 28 from both sides.
-20n = -160
Divide by -20 on both sides.
n = 8
