Question

Спростити вираз: (x-3) (4x в квадрате -6x)-2x(2x-5) (x-2

Answer 1

$(x-3)(4x^2-6x)-2x(2x-5)(x-2)= \\ 4x^3-12x^2-6x^2+18x-(4x^2-10x)(x-2)= \\ \\ 4x^3-18x^2+18x-(4x^3-10x^2-8x^2+20x)= \\ \\ 4x^3-18x^2+18x-4x^3+10x^2+8x^2-20x= \\ \\ -18x^2+18x+18x^2-20x= \\ \\ -2x$

Answer 2

$(x-3)(4 x^{2} -6x)-2x(2x-5)(x-2)= \\ =4 x^{3} -6 x^{2} -12 x^{2} +18x-2x(2 x^{2} -4x-5x+10)= \\ =4 x^{3} -18 x^{2} +18x-2x(2 x^{2} -9x+10)= \\ =4 x^{3} -18 x^{2} +18x-4 x^{3} +18 x^{2} -20x= \\ =18x-20x=-2x$