Will give brainliest b. describe the function over each part of its domain. state whether it is constant, increasing, or decreasing, and state the slope over each part.

When x <= 8000

The cost remains constant at 0.35 when x increases from 0 to 8000

The slope of cost function over this part is 0

When 8000 < x <= 20000

The cost remains constant at 0.75 when x increases from 8000 to 20000

The slope of cost function over this part is 0

When 20000 < x <= 42000

The cost decreases when x increases from 20000 to 42000

The slope of cost function

m= -5 × 10^-6

$53.50

step-by-step explanation:

you have to subtract the amount of money chuck earned ($72.50) by the cost of the gas for the mower ($11.25) and the new string for the trimmer he bought ($7.75).

72.50-11.25=61.25

and then subtract $61.25 by the second thing he bought (the new string for the trimmer)

61.25-7.75=53.5

so in total it's $53.50 (53 dollars and 50 cents)