Question

Earl mows lawns one weekend. He earns $12 for each lawn that he mows. He spends $40 on gas and other supplies.

What function equation represents Earl's profit from mowing x lawns?

A. f(x) = 40x − 12

B. f(x) = 12x − 40

C. f(x) = 12x + 40

D. f(x) = 40x +12

Answer 1

Multiply the numbers of lawns x by 12 dollars - this will give you his earnings
His profit will be these earnings minus his expenses ($40).

Answer 2

so his earnings = ?

Answer 3

what is 12 times x as an algebraic term?

Answer 4

What do you mean by "algebraic term"?

Answer 5

well
4x , 12y , ax, x^2 are all algebraic terms

Answer 6

12 times x is written as 12x - that's all

Answer 7

so we have f(x) = 12x so far
now we have to subtract 40

Answer 8

So like this, f(x) = 12x - 40?

Answer 9

Yes. Note that "Profit" equals "Total revenue" less "Costs".

Be sure to follow that formula.

Answer 10

Your formula is a good one. Note that until 12 times x is greater than $40, this guy makes NO profit.

Answer 11

Oh, I get it now..
So it's B, right?

Answer 12

Yes B is correct

Answer 13

whether he makes a profit or not depends on how many lawns he mows

Answer 14

Thank you.

Answer 15

yw