Which angles are supplementary to each other?

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.

Solve for x and y: 217x + 131y = 913; 131x + 217y = 827

Table which ratio is equivalent to 3: 7? 6: 7 3: 21 24: 56 15: 30