2/5 : 1/3 5/6 : 3/8 3 цел 1/9 : 2 цел 1/6 1 цел5/12 : 2/15 1/8 : 1 цел 7/12
2/5*3=6/5=1 1/5 5/6*8/3=40/18=20/9=2 2/9