Question 112312
.08X+.09(9000-X)=770
.08X+810-.09X=770
-.01X=770-810
-.01X=-40
X=-40/-.01
X=4000 AMOUNT INVESTED @ 8%
9000-4000=5000 INVESTED @ 9%
PROOF
.08*4000+.09*5000=770
320+450=770
770=770