Х:12=75:15 12,4:х=5,58:0,9 2/8*5/9=х:1/3

х:12=5, х=5*12, х=60 12,4:х=6,2, х=12,4:6,2, х=2 1/4*5/9=х*3/1, 5/36=3х, х=5/36:3, х=5/36*1/3, х=5/108