1/3x+1/5x=22/15 5/6（x-1）=5/18 2.4×5-3/4x=9 1/13x/4/5=10/13

1/3x+1/5x=22/15 8/15x=22/15 x=22/15*15/8 x=11/4 5/6（x-1）=5/18 5/6x-5/6=5/18 5/6x=5/18+5/6 5/6x=10/9 x=10/9*6/5 x=4/3 2.4×5-3/4x=9 12-3/4x=9 3&#