Plz help ASAP with explanation

Can somebody me out with this question

The functions below show the amount of money bella and sweet t had saved after earning money for doing chores. which description best compares the two functions?

Sanderson is having trouble with his assignment. his shown work is as follows: − 3 7 7 3 = − 3 7 × 7 3 = − 21 21 = −1 however, his answer does not match the answer that his teacher gives him. complete the description of sanderson's mistake. find the correct answer.