1)x^3+x^2y+xy^2+y^3 = x^2(x+y)+y^2(x+y)=(x^2+y^2)(x+y)
2) x^3-2x^2y+y^2x-2y^3 = x^2(x-2y)+y^2(x-2y)= (x-2y)(x^2+y^2)
3) x^4y^2+2x^4+x^2y^2+2x^2 =x^2(x^2+1)(y^2+2)
4)2x^2+7x-4
D=49+4*2*4=9^2
x=-7+9/4=1/2
x2=-7-9/4 = -4
(x+4)(2x-1)
5) 4x^2+y-2x-y^2 решим кв уравнение относительно x
4x^2-2x+y-y^2 =0
D=4-4*4(y-y^2)=4-16y+16y^2 =4(1-4y+4y^2)= 4 (2y-1)^2
отудого (2x-y)(y+2x-1)
6) x^2-9x+9y-y^2 = (x-y)(x+y)-9(x-y)=(x-y)(x+y-9)
7) 3ax-2-x+6a = 3a(x+2)-(x+2) = (x+2)(3a-1)