( .06 * X ) + ( .09 * (4000 - X) ) = 270
360 - .03X = 270
.03X = 90
X = 3000
3000 at 6% and 1000 at 9%
Check: (3000 * .06) + (1000 * .09) = 180 + 90 = 270
Jerry is correct, but I thought I'd show you a step that he omitted:
( .06 * X ) + ( .09 * (4000 - X) ) = 270
0.06x + 360 - 0.09x = 270
360 - 0.03x = 270
360 - 270 = 0.03x
90 = 0.03x
90 / 0.03 = x
x = 3000
thus (4,000 - x) = 1,000
Siri invests $4000 in 2 accounts, one at 6% interest, the other at 9% interest for 1 year. At the end of the year she had earned $270 in interest. How much did Siri invest in each account?
1. Label the variables in the problem.
2. Write the system of equations that models the problem.
