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1. a) (15y^2+7y)-(13y-5y^2)=15y^2+7y-13y+5y2
20y^2-6y
b)2c(a-3b+4)=2ca-6cb+8c
2. a) xy(2-3xy)
b) 2b3(4b+1)
3.
7-4(3x-1)=5(1-2x)
7- 12x + 4 = 5 - 10x
-2x=6
x=-3
На ноль делить нельзя, х=-6
= -3ху+ 15ха-14аb+21ac-24pa+36pb+84pc