Please help me out with this math problem Please NO LINKS!! :)

Kevin has just finished paying off his loan. he was assessed a service charge of $422. he paid off the principal and the interest by making weekly payments of $36.13 for four years. if the principal was $7,150, how much did kevin pay in finance charges, to the nearest dollar? a. $498 b. $365 c. $422 d. $787

Lorne subtracted 6x3 – 2x + 3 from –3x3 + 5x2 + 4x – 7. use the drop-down menus to identify the steps lorne used to find the difference.

Ineed to know the answer to this algebra question.