You invested $7000 between two accounts paying 2% and 9% annual interest if the total earned for the year was $420, how much was invested at each rate

Question

You invested $7000 between two accounts paying 2%and 9% annual interest. If the total interest earned for the year was $420, how much was invested at each rate

Answer 1

.09x + .02(7000-x) = 420

.09x -.02x = 420-140

,07x = 280

x = 280/.07 = 28,000/7 = $4000 invested at 9%

7000-4000 = $3,000 invested at 2%

check the answers

420/7000 = 6%= average interest on $7000

9-6=3

6-2 =4

4/3 times as much invested at 9% as 2%

4000/3000= 4/3

.09(4000) +.02(3000)

= 360+60=420