1 9/40 * 1 1/7 2 34/49 * 1 3/4 3 13/15* 1 1/4 помогите 11 б

1 9/40*1 1/7=49/40*8/7=(49*8)/(40*7) = (7*7*8)/(5*8*7) = сокращаем на 7 и на 8 = 7/5=1 2/52 34/49* 1 3/4 = 132/49*7/4=(132*7)/(49*4) = (4*33*7)/(7*7*4) = 33/7=4 5/73 13/15*1 1/4=58/15*5/4 = (58*5)/(15*4)=(2*29*5)/(3*5*2*2) = 29/6=4 5/6