The area of a rectangle is 8X^3+6^X+^2-10x. The width of the rectangle is 2x. Find the length of the rectangle. Please help.

Ricky takes out a $31,800 student loan to pay his expenses while he is in college. after graduation, he will begin making payments of $190.66 per month for the next 30 years to pay off the loan. how much more will ricky end up paying for the loan than the original value of $31,800? ricky will end up paying $ more than he borrowed to pay off the loan.