Условие:

5.31 а) 10y5/9a: 5y3/3b*3a2/by;

б) 25a3b3/14x2y4*21xy3/10a2b2*8xy2/15ab;

в) 28a2/27x3:21x4/45y*x8/20ya;

г) 45m4/49n2t*56n3/27m2:20m2n/63t2.