A man invested half of his money at 5%, one-third of his money at 4%, and the rest of his money at 5.5%. If his total investment income was $570, how much had he invested?

and please show me the solution to solve this problem. thanx

M*1/2(1.05)+ M(1/3)(1+.04)+ m(1-1/2-1/3)(1.055)=570

solve for M.