SOLUTION: I dont understand this: Kendra invested $850, part of it at 9% and part of it at 12%. If her interest for one year was $81 how much did she invest at each rate?

Algebra ->  Customizable Word Problem Solvers  -> Finance -> SOLUTION: I dont understand this: Kendra invested $850, part of it at 9% and part of it at 12%. If her interest for one year was $81 how much did she invest at each rate?      Log On

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Question 125214: I dont understand this:
Kendra invested $850, part of it at 9% and part of it at 12%. If her interest for one year was $81 how much did she invest at each rate?

Answer by checkley71(8403) About Me  (Show Source):
You can put this solution on YOUR website!
.12X+.09(850-X)=81
.12X+76.5-.09X=81
.12X-.09X=81-76.5
.03X=4.5
X=4.5/.03
X=150 AMOUNRT INVESTED @ 12%.
850-150=700 INVESTED @ 9%.
PROOF
.12*150+.09*700=81
18+63=81
81=81