№1 разложите на множители: 1) 8(у-3)-а(3-у) 2) 6(а-2)+5а(2-а) 3) 2(х+у)(х-+у)^2 4) 3ах-ау+3bх-bу 5) ab-ac-7b+7c №2 выполните умножение: 1) (3х-2у)(3х+2у) 2) (z-4b)(4b+z) 3) (-2n+3p^2)(3p^2+2n) 4) (5a^2-0,4b^2)(0,4b^2+5a^2) 5) (2,5x-0,3y)(2,5x+0,3y)

1) 8(y-3)-a(3-y)=8(y-3)+a(y-3)=(y-3)(8+a)
2) 6(a-2)+5a(2-a)=6(a-2)-5a(a-2)=(a-2)(6-5a)
3) 2(x+y)(x-y)-(x+y)^2=(x+y)(2(x-y)-(x+y))=(x+y)(2x-2y-x-y)=(x+y)(x-3y)
4) 3ax-ay+3bx-by=a(3x-y)+b(3x-y)=(3x-y)(a+b)
5) ab-ac-7b+7c=a(b-c)-7(b-c)=(b-c)(a-7)

1) (3х-2у)(3х+2у)=(3x)^2-(2y)^2=9x^2-4y^2
2) (z-4b)(4b+z)=(z-4b)(z+4b)=z^2-16b^2
3) (-2n+3p^2)(3p^2+2n)=(3p^2-2n)(3p^2+2n)=9p^4-4n^2
4) (5a^2-0,4b^2)(0,4b^2+5a^2)=(5a^2-0.4b^2)(5a^2+0.4b^2)=25a^4-0.16b^4
5) (2,5x-0,3y)(2,5x+0,3y)=6.25x^2-0.09y^2