Question 167223
so lets call P the initial investment

(((((P+P)-4000)3)-10000)2)-4000=12000

(2P-4000 ) (3)=6P-12000

now subtract 10000 =6P-22000.  multiply that by 2=12P-44000 subtract 4000 and that equals 12P-48000=12000  so 12P=60000 {{{highlight(P=5000)}}}