For this case we have the following quadratic functions:
Revenue: 
Cost: 
Then, we observe that the profit is given by the following mathematical relationship:

Substituting values we have:

Making the corresponding calculations we have:

Answer:
An expression that represents the profit is:

The truck was going 40 miles per hour
The amount of time was 2 hours:
(90-80: 10)(10/2=5)
80 divided by two is 40
The car was going 45 miles per hour
(90-80:10)(10/2=5)
90 divided by two is 45
Hopefully you find this helpful
Answer:
Step-by-step explanation:
area of top=7×6=42 yd²
area of bottom=3×6=18 yd²
area of two rectangles=2[4×6]=48 yd²
area of two trapezoids=2[1/2(7+3)×3.5]=35 yd²
total surface area=42+18+48+35=143 yd²