Đáp án:
Giải thích các bước giải:
c) x(x + 5)(x – 5) – (x + 2)(x² – 2x + 4)
⇔(x – 5)x²+5x(x-5)-(x+2)(x² – 2x + 4)
⇔x³-5x²+5x(x-5)-(x+2)(x² – 2x + 4)
⇔x³-5x²+5x²-25x-(x+2)(x² – 2x + 4)
⇔x³-25x-(x+2)(x² – 2x + 4)
⇔x³-25x-[x(x²-2x+4)+2(x²-2x+4)]
⇔x³-25x-[x³-2x²+4x+2x²-4x+8)]
⇔x³-25x-(x³+4x-4x+8)
⇔x³-25x-(x³+8)
⇔x³-25x-x³-8
⇔-25x-8
xin ctlhn ạ