Robert invested $10000 and earned a total of $550 interest. He invested part of the $10000 in an account paying 5% and rest in an account paying 6%. How much did he invest in each account.

Answer 1

(x * .05) + [(10000 - x) * .06] = 550

Answer 2

if x at 5% then the rest (10000-x) is at 6%. So, add up the interest:

.05x + .06(10000-x) = 550

Answer 3

.05x +.06(10,000-x) = 550
.05 x + 600 -.06 x = 550

50 = .01 x
x = 5000