An Investor invested a total of $2,600 in two mutual funds. One fund earned 7% profit while the other earned 3% profit. If the investor's total profit was $150, how much was invested in each mutual fund?

let x = amount invested at 3%

so, (2600 - x) is invested at 7%

.07 * (2600 - x) +.03 * (x) = 138

182 -.07x +.03x = 138

-.07x +.03x = 138 - 182

-.04x = - 44

-.04x / -.04 = - 44 / -.04

x = 1,100

so amount invested at 7% is (2600 - 1100) or 1500

consequently amount invested at 3% is 1100

$1,100 invested at 3%

$1,500 invested at 7%