math
posted by Robert on .
Amy has $200 less invested at 9% than she does at 6.5%. If the annual return from the two investments is the same, how much is invested at each rate?

If she invested $X at 9%, then she invested $(X+200) at 6.5%.
Since the return is the same, then
X*0.09 = (X+200)*0.065
X(0.090.065)=200*0.065
0.025X = 13
X = 13/0.025 = $520 at 9%
X+200 = $720 at 6.5%