goi so nguoi doi 1,2 3 la x,y,z ta co pt;
2x/3 = 3y/4 = 4z/5 ma x =72
y=? z=? lam dc chu ban cua tui
neu chuyen 1/3 ng doi 1 thi doi 1 con lai la 3/3 - 1/3 = 2/3 tuong tu voi doi 2 va 3
goi so ng moi doi la x,y,z ta co pt;
2x/3 = 3y/4 = 4z/5 ma x = 72
vay y =? z=? lam dc chu ban cua tui