Answer:
Step-by-step explanation:
Let x represent the amount invested at 11%. Then (5400-x) is the amount invested at 8%. The total interest earned is the sum of the interest amounts earned on each investment. Each of those is the product of the interest rate and the amount invested.
(5400-x)·8% + x·11% = 522
432 +0.03x = 522 . . . . . . . . simplify
.03x = 90 . . . . . . . . . . . . . . . subtract 432
90/.03 = x = 3000 . . . . . . . . divide by the coefficient of x
$3000 is invested at 11%; $2400 is invested at 8%.