SOLUTION: Roberto invested some money at 7%, and then invested $2,000 more than twice his amount at 11%. His total annual income from the two investemnts was $3,990. How much was invested at

Algebra ->  Customizable Word Problem Solvers  -> Misc -> SOLUTION: Roberto invested some money at 7%, and then invested $2,000 more than twice his amount at 11%. His total annual income from the two investemnts was $3,990. How much was invested at      Log On

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Question 130342: Roberto invested some money at 7%, and then invested $2,000 more than twice his amount at 11%. His total annual income from the two investemnts was $3,990. How much was invested at 11%.
Answer by checkley71(8403) About Me  (Show Source):
You can put this solution on YOUR website!
.07X+.11(2X+2000)=3990
.07X+.22X+220=3990
.29X=3990-220
.29X=3770
X=3770/.29
X=13,000 INVESTED @ 7%.
2*13000+2000=26000+2000=28,000 IS THE AMOUNT INVESTED @ 11%.
PROOF:
.07*13000+.11*28000=3990
910+3080=3990
3990=3990