А)(х-3)(х+3)-3х(4-x) = x^2-9-12x+3x^2 = 4x^2-12x-9.
б) -4y(y+2)+(y-5)^2 = -4y^2-8y+y^2-10y+25 = -3y^2-18y+25.
В) 2(а-3)^2-2a^2 = 2(a^2-6a+9)-2a^2 = 2a^2-12a+18-2a^2 = -12a+18.
А) Х^4-16Х^2 = x^2(x^2-16) = x^2(x-4)(x+4).
Б) -4х^2-8xy-4y^2 = -4(x^2+2xy+y^2) = -4(x+y)^2.
А) (х+5)(х^2-5х+25)-х(х^2+3) = x^3+125-x^3-3x = 125-3x.
А) (а-5)^2-16б^2 = (а-5-4б)(а-5+4б).
Б) х^2-y^2-5х-5y = (x-y)(x+y)-5(x-y) = (x-y)(x+y-5).