a person invested $6,900 for 1 year, part at 7% part at 9% and the remainder at 12%. The total annual income from these investments was $712. The amount of money invested at 12% was $900 more than the amounts invested at 7% and 9% combined. Find the amount invested at each rate

Question

anonymous · Answer

Either use PRI or Systems of Three Variables

hero · Answer

System of three variables in this case

x + y + z = 6900
.07x + .09y + .12z = 712
z = x + y + 900

anonymous · Answer

thank you!

anonymous · Answer

how do you do the pri

hero · Answer

I'm not sure how to do PRI version. It would be interesting to see how that is done.

anonymous · Answer

I know how to do it but i forgot

anonymous · Answer

I was really good at it last spring

hero · Answer

The systems of equations method is easier and more straight forward anyways.

anonymous · Answer

ok Im going to try to work it out in the equation.

anonymous · Answer

i got x=1350 y=1650 z=3900 but when i submitted it it said it was wrong!