Question 113012
.07x+.11y=3990
Let x=amount invested at 7%
Let y=amount invested at 11%; y=2x+2000

.07x+(2x+2000).11=3990
.07x+.22x+220=3990
.07x+.22x=3770
.29x=3770
x=$13,000-> plug back into original equation

.07(13,000)+.11y=3990
910+.11y=3990
.11y=3080
y=$28,000

$28,000 invested at 11%