A man invests $21,000 in two accounts. One account earns 5% interest per year and the other earns 6.5%. If his total interest after one year is $1,230, how much did he invest at each rate?

Answer 1

x+y=21 (right side is in thousands of dollars)

.05x+.065y =.1.23

.05(21-y) + .065y = 1.23

.015y = 0.18

y = 180/15 = $12,000 at 6.5%

x = $9,000 at 5%