Substitution or elimination

Question

Jenelle invested $19600 in two mutual funds. Fund A earned 4% profit during the first year, while Fund B suffered a 1.5% loss. If she received a total of $487 profit, how much had she invested in each mutual fund? 

Answer 1

let x = share invested in A and (1-x = share invested in b. Total portfoilo return was 487 on 19600 or 2.484% so x*4% *x +(1-x)(11.5%) =2.84% expanding we get

2.484% = - .1.5% +X*(4% +1.5%) or

3.984% = x*(5.5%) or x = 3.984%/5.5% = 72.4 % was invested in Fund A and the balance in fund B