SOLUTION: Roberto invested some money at 6%, and then invested $4000 more than twice this amount at 12%. His total annual income from the two investments was $3480. How much was invested at

Algebra ->  Coordinate Systems and Linear Equations  -> Linear Equations and Systems Word Problems -> SOLUTION: Roberto invested some money at 6%, and then invested $4000 more than twice this amount at 12%. His total annual income from the two investments was $3480. How much was invested at      Log On


   

Question 364336: Roberto invested some money at 6%, and then invested $4000 more than twice this amount at 12%.
His total annual income from the two investments was $3480. How much was invested at 12%?
Answer by mananth(16946) About Me  (Show Source):
You can put this solution on YOUR website!
$x @ 6 %
2x+4000 @ 12%
interest = 3480
...
0.06x+0.12(2x+4000) = 3480
multiply by 100
6x+12(2x+4000)=348000
6x+24x+48000=348000
30x = 300,000
x= 30,000 investment @ 6%
2x+4000= 60,000+4000= $64,000 @12%
...
m.ananth@hotmail.ca