Answer:
$15 for a lawn, $105 for seven lawns.
Step-by-step explanation:
The question is about the direct ratio problem. Logically, you will earn more if you mow more lawn.
The scheme for this ratio is given below:
15 n_________n lawns
x_________ 1 lawn

You will earn 15 dollars for mowing a lawn
When you mow 7 lawns, the scheme will be in this manner:
15 n__________n lawns
x__________7 lawns

You will earn 105 dollars
54 = 2 × 3 × 3 × 3 ( as a product of its prime factor ).
So, the function is obviously shifted up by 1 so it rules out A and B, and we also see that the period is 4pi rather than 2pi, and using the fact that:

Now that we know our b value, we see that the correct answer would be C.
The answer is Y=-2/5x+1 :)