Упрожнение 171 только а)
Х:(-(75/49)*91/50*36/13) = -(84/55)*88/63*15/64 х:(-(3*18)/7) = -((21*3)/(63*2)) х:(-(54/7) = -(1/2) х = 54/14 = 27/7 = 3 6/7