Which of these expressions correctly represents the phrase “17 less than three times a number”?

3n - 17

Step-by-step explanation:

This phrase includes subtraction (“less than”) and multiplication (“times”). We are multiplying a number (3) by the variable to create the term 3n. Subtraction is not commutative, so order does matter. 17 less than 3n means we have 3n and take 17 away: 3n - 17.

$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)