Đáp án:
Giải thích các bước giải:
$\text{-4x(x+3)(x-4)-3x(x²-x+1)}$
$\text{= (-4x²-12x)(x-4)-3x³+3x²-3x}$
$\text{= -4x³+16x²-12x²+48x-3x³+3x²-3x}$
$\text{= -7x³+7x²+45x}$
$\text{4x(x²-x+3)-(x-6)(x-5)}$
$\text{= 4x³-4x²+12x-x²+5x+6x-30}$
$\text{= 4x³-5x²+21x-30}$
$\text{-3(x+1)(x-7)+7(x-5)(x-1)}$
$\text{=(-3x-3)(x-7)+(7x-35)(x-1)}$
$\text{=-3x²+21x-3x+21+7x²-7x-35x+35}$
$\text{= 4x²-24x+56}$