1) 7z/4(x-y)
3) 34b/105(b+c)
1) 6y+x/2xy*(x - y)
2) 4b+c/2bc*(3c-1)
1) - a+2ab/b2-ab
3) 5b2-3a2/ab*(x-y)
1) 5x+3/2(x2-9)
3)2+2c2+5c/4c2-25
1)3m-8m3+2m2+27/(2m-9)*(9-4m2)
2) 23n+6n2-5/(3n+5)*(3n-5)2
1) 5+12z-2z2/(6-z)2
2)21+93m+2m2-28m2/21m2-m3-146m+336
3)-3a+15a2/(-3a+1)2*(1+3a)
4) не знаю