Question 69242
.12X+.10Y=130
.10X+.12Y=134 OR
.12X+.10Y-(.10X+.12Y)=-4
.12X-.10X+.10Y-.12Y=-4
.02X-.02Y=-4
.02X=.02Y-4
X=.02Y/.02-4/.02
X=Y-200 NOW SUBSTITUTE (Y-200) FOR X IN EITHER EQUATION. THUS:
.12(Y-200)+.10Y=130
.12Y-24+.10Y=130
.22Y=130+24
.22Y=154
Y=154/.22
Y=$700 INVESTED @ 10% TO GET THE $130 INTEREST.
X=7-200
X=500 INVESTED @ 12% TO GET $130  INTEREST.
PROOF
.10*500+.12*700=134
50+84=134
134=134