5+1.5(2d-1)=0.5can anyone ! i need asap

Rewrite the following without an exponent. (5/8)-1

Barbara deposited $300 in the bank. if the bank pays her simple interest at the rate of 4 percent per year, how much money will she have in her account at the end of 9 months?

If cos(2x) = tan^2(y), show that cos(2y) = tan^2(x).