\(\text{e) 2x^4 + 5x^3+13x^2+25x+15 }\)
  \(\text{=2x^3(x+1)+3x^2(x+1)+10x(x+1)+15(x+1) }\)
  \(\text{=(x+1)[x^2(2x+3)+5(2x+3)]}\)
  \(\text{=(x+1)(2x+3)(x^2+5)}\)

\(2x^4+5x^3+13x^2+25x+15\)

\(=2x^4+2x^3+3x^3+3x^2+10x^2+10x+15x+15\)

\(=2x^3\left(x+1\right)+3x^2\left(x+1\right)+10x\left(x+1\right)+15\left(x+1\right)\)

\(=\left(x+1\right)\left(2x^3+3x^2+10x+15\right)\)

Làm tiếp

\(=\left(x+1\right)\left[x^2\left(2x+3\right)+5\left(2x+3\right)\right]\)

\(=\left(x+1\right)\left(2x+3\right)\left(x^2+5\right)\)

\(=2x^4-6x^3-x^3+3x^2-5x^2+15x-2x+6\)

\(=2x^3\left(x-3\right)-x^2\left(x-3\right)-5x\left(x-3\right)-2\left(x-3\right)\)

\(=\left(x-3\right)\left(2x^3-x^2-5x-2\right)\)

\(=\left(x-3\right)\left(2x^3-4x^2+3x^2-6x+x-2\right)\)

\(=\left(x-3\right)\left[2x^2\left(x-2\right)+3x\left(x-2\right)+\left(x-2\right)\right]\)

\(=\left(x-3\right)\left(x-2\right)\left(2x^2+3x+1\right)\)

\(=\left(x-3\right)\left(x-2\right)\left(x+1\right)\left(2x+1\right)\)

\(b,=x^4-2x^3-x^3+2x^2+3x^2-6x-3x+6\\ =\left(x-2\right)\left(x^3-x^2+3x-3\right)\\ =\left(x-2\right)\left(x-1\right)\left(x^2+3\right)\\ c,=x^4-2x^3+4x^3-8x^2+4x^2-8x+3x-6\\ =\left(x-2\right)\left(x^3+4x^2+4x+3\right)\\ =\left(x-2\right)\left(x^3+3x^2+x^2+3x+x+3\right)\\ =\left(x-2\right)\left(x+3\right)\left(x^2+x+1\right)\)

bằng phương thức nào bạn ?

câu trả lời:

3x.x-13.x+6²

bằng phương pháp đặt nhân tử chung

\(=\left(13x^2-13x\right)-\left(14x-14\right)=13x\left(x-1\right)-14\left(x-1\right)=\left(13x-14\right)\left(x-1\right)\)

THAM KHẢO NHÉ BẠN, MÌNH KO VT ĐC TRONG NÀY NÊN PHẢI RA WORD VÍT R COPY VÀO Á:

$7x^2-13x+6=0\iff 7x^2-7x-6x+6=0$

$\iff 7x\left(x-1\right)-6\left(x-1\right)=0\iff \left(7x-6\right)\left(x-1\right)=0$

x=1;x=67

`#040911`

`7x^2 - 13x + 6`

`= 7x^2 - 7x - 6x + 6`

`= (7x^2 - 7x) - (6x - 6)`

`= 7x(x - 1) - 6(x - 1)`

`= (7x - 6)(x - 1)`

\(7x^2-13x+6=7\left(x-1\right)\left(x-\dfrac{6}{7}\right)\)

\(=6x^2+3x+10x+5=3x\left(2x+1\right)+5\left(2x+1\right)=\left(3x+5\right)\left(2x+1\right)\)

6x2+3x+10x+5=3x(2x+1)+5(2x+1)=(3x+5)(2x+1)

=6x^2 - 4x - 9x +6

=(6x^2 -4x) - (9x-6)

=2x(3x -2) - 3(3x-2)

=(3x-2) (2x - 3)