а) (a-x)(a+x^2) + (x-a)x^2 = (a-x)(a+x^2) - (a-x)x^2 = (a-x)(a+x^2-x^2) = (a-x)(a) = a^2 - ax
к) a(a^2+3ab)-a^3 = a^3 + 3a^2b - a^3 = 3a^2b
л) c^3(d-4)^3 + c^2(d-4)^4 = c^2(d-4)^3(c+(d-4)) = c^2(d-4)^3(c+d-4)
а) (a-x)(a+x^2) + (x-a)x^2 = (a-x)(a+x^2) - (a-x)x^2 = (a-x)(a+x^2-x^2) = (a-x)(a) = a^2 - ax
к) a(a^2+3ab)-a^3 = a^3 + 3a^2b - a^3 = 3a^2b
л) c^3(d-4)^3 + c^2(d-4)^4 = c^2(d-4)^3(c+(d-4)) = c^2(d-4)^3(c+d-4)