Last year tammy had $4,500 to invest in two savings accounts. one account earns 7% simple annual interest, and the other account earns 6% simple annual interest. at the end of the year, tammy had earned a total of $290 in interest from the two savings accounts. part a write a system of two equations that could be used to find the amount of money invested in each account. let x represent the amount invested at 7%, and let y represent the amount invested at 6%. part b solve the system of equations. how much did tammy have invested at each rate?