SOLUTION: One year ago Walt invested $12,000. He invested part of the money at 7% and the rest at 9%. He made a total of $970 in interest. How much was invested at 7%?

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Question 193525: One year ago Walt invested $12,000. He invested part of the money at 7% and the rest at 9%. He made a total of $970 in interest. How much was invested at 7%?
Answer by RAY100(1637) About Me  (Show Source):
You can put this solution on YOUR website!
let x= amount invested at .07
let y = amount invested at .09
x+y=$12,000,,,,or x=12000-y
total made is 970=.07x+.09y
subst
970=.07(12000-y)+.09y
970=840-.07y+.09y
130=.02y
y=6500
x=12000-6500=5500
check
.07*5500+.09*6500
385+585=970,,,,ok