Investor invested $2200 into 2 mutual funds, 1 earned 7% profit, the other 3% profit, total profit was $142, how much was invested into each fund

The entire amount invested earned interest at the rate of 3%. Some portion, X earned additional interest, at the additional rate of 4% (7-3=4). The additional interest earned is the difference between the total interest earned and the 3% earned by the total investment. So if X times .04 is equal to additional interest then X is equal to additional interest divided by .04.