a) xу + 3y + x = 3 =
b) 25-c^2=
c) ab^2-2abc+ac^2
d) 3a^3-12a^2b+6ab
g) x(x-1)+2(x-1)

а) xy +3y+x+3= y(x+3)+(x+3)= (x+3)(y+1)
b) = (5+c)(5-c)
c) a( b^2-2bc+c^2)= a(b-c)^2
d) 3a( a^2- 4ab + 2b) 
g) = (x-1)(x+2)