=x3(x+2)-13x2+12x-26x+24
=x3(x+2)-x(13x-12)-2(13x-12)
=x3(x+2)-(13x-12)(x+2)
=(x+2)(x3-x-12x+12)
(x+2)[(x2-1)-12(x-1)]
=(x+2)[x(x-1)(x+1)-12(x-1)]
=(x+2)(x-1)[x(x+1)-12]
=(x+2)(x-1)(x2+x-12)
=(x+2)(x-1)(x2-3x+4x-12)
=(x+2)(x-1)[x(x-3)+4(x+3)]
=(x+2)(x-1)(x-3)(x+4)
trong bài làm của mk có hàng k có dấu "=" chỗ đó có dâu"=" nha!
x4 + 2x3 - 13x2 - 14x + 24
= x4 - x3 + 3x3 - 3x2 - 10x2 + 10x - 24x + 24
= x3(x - 1) + 3x2(x - 1) - 10x(x - 1) - 24(x - 1)
= (x - 1)(x3 + 3x2 - 10x - 24)
= (x - 1)(x3 + 2x2 + x2 + 2x - 12x - 24)
= (x - 1)[x2(x + 2) + x(x + 2) - 12(x + 2)]
= (x - 1)(x + 2)(x2 + x - 12)
= (x - 1)(x + 2)(x2 + 4x - 3x - 12)
= (x - 1)(x + 2)[x(x + 4) - 3(x + 4)]
= (x - 1)(x + 2)(x - 3)(x + 4)
\(x^4+2x^3-13x^2-14x+24\)
\(=x^3\left(x+2\right)-13x\left(x+2\right)+12\left(x+2\right)\)
\(=\left(x+2\right)\left(x^3-13x+12\right)\)
\(=\left(x-3\right)\left(x-1\right)\left(x+2\right)\left(x+4\right)\)
