举报
cwy_
9分之4乘8分之5再乘18 =4/9x18x5/8 =8x5/8 =5 {7分之8减去5分之4}乘8分之7 =8/7x7/8-4/5x7/8 =1-7/10 =3/10 7分之3乘15减去7分之3 =3/7x(15-1) =3/7x14 =6 3分之8乘{3分之2减去21分之8乘16分之8} =8/3x{2/3-4/21} =8/3x10/21 =80/63 15分之14乘17分之7乘28分之5乘17 =14/15x5/28x(7/17x17) =1/6x7 =7/6 99乘10分之7 =100x7/10-7/10 =70-0.7 =69.3 有问题重新发,不要追问了