Question 160290
.12*2x+.09x+.10(x+500)1,555
.24x+.09x+.10x-50=1,555
.43x=1,555-50
.43x=1,505
x=1,505/.43
x=3,500 is the amount invested @ 9%
2*3,500=7,000 invested @ 12%
3,500+500=4,000 invested @10%
Proof:
.12*7,000+.09*3,500+.10*4,000=1,555
840+315+400=1,555
1,555=1,555