Two investments are made totaling $4800. In the first year they yield a total of $412 in simple interest. Part of the money is invested at 8% and the rest at 9%. Find the amount invested at each interest rate.

Answer 1

add up the interest gained on each part. Their sum must be the total earned. If $x is at 8%, then that leaves 4800-x at 9%, so

.08x + .09(4800-x) = 412
x = 2000