
Phillip R. answered 09/14/14
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let x = total amount invested
interest from each investment = amount x rate
The total interest = $6550
25%x(4%) + 40%x(6%) + 35%x(9%) = 6550 now solve for x
.25x(.04) + .40x(.06) + .35x(.09) = 6550
25x(4) + 40x(6) + 35x(9) = 6550 x 100 x 100
100x + 240x + 315x = 65,500,000
655x = 65,500,000
x = $100,000 is total amount invested