Question

tìm x 

2x² - x - 6 = 0

 

Answer 1

`2x^2-x-6=0`

`<=>2x^2-4x+3x-6=0`

`<=>2x(x-2)+3(x-2)=0`

`<=>(x-2)(2x+3)=0`

`<=>[(x-2=0),(2x+3=0):}<=>[(x=2),(x=-3/2):}`

Answer 2

\(2x^2-4x+3x-6=0\\ 2x\left(x-2\right)+3\left(x-2\right)=0\\ \left(2x+3\right)\left(x-2\right)=0\\ \left[{}\begin{matrix}2x+3=0\\x-2=0\end{matrix}\right.=>x=-\dfrac{3}{2};x=2\)

Answer 3

`2x^2 - x - 6 = 0`

`-> 2x^2 - 4x + 3x - 6 = 0`

`-> (x-2)(2x+3) = 0`

`->` \(\left[{}\begin{matrix}x=2\\x=-\dfrac{3}{2}\end{matrix}\right.\)

Answer 4

2x² - x - 6 = 0

<=> (2x² - 4x) + (3x - 6) = 0

<=> 2x(x - 2) + 3(x - 2) = 0

<=> (2x + 3)(x - 2) = 0

<=> 2x + 3 = 0 hoặc x - 2 = 0

\(\Leftrightarrow x=-\dfrac{3}{2}\) hoặc x = 2

Vậy phương trình có tập nghiệm là: \(S=\left\{-\dfrac{3}{2};2\right\}.\)