(u+12)11 whole number coefficients

Find the value of the cosine for angle a

The amount of money, in dollars, in an account after t years is given by a = 1000(1.03)^t. the initial deposit into the account was $_^a0 and the interest rate was _a1% per year. only enter numbers in the boxes. do not include any commas or decimal points^t. the initial deposit into the account was $__^a0 and the interest rate is % per year.

Find the solution of this system of equation -7x+y=-20 9x-3y=36