SOLUTION: 3. Walt made an extra $12,000 last year from a part-time job. 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
Algebra ->
Quadratic Equations and Parabolas
-> SOLUTION: 3. Walt made an extra $12,000 last year from a part-time job. 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
Log On
Question 180998: 3. Walt made an extra $12,000 last year from a part-time job. 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 josmiceli(19441) (Show Source):
You can put this solution on YOUR website! Let = amount invested @ 7%
Let = amount invested @ 9%
given:
(1)
(2)
Multiply both sides of (2) by
and subtract from (1)
(1)
(2)
And, subtracting:
(1)
(2)
And, since
(2)
$5500 was invested @ 7%
check:
(1)
OK
