Question

Tìm x

x² -5x +6 = 0

Answer 1

\(x^2-5x+6=0\)

Cách 1: \(x^2-5x+6=0\)

\(\Leftrightarrow x^2-\left(2x+3x\right)+6=0\)

\(\Leftrightarrow x^2-2x-3x+6=0\)

\(\Leftrightarrow\left(x^2-2x\right)-\left(3x-6\right)=0\)

\(\Leftrightarrow x\left(x-2\right)-3\left(x-2\right)=0\)

\(\Leftrightarrow\left(x-2\right)\left(x-3\right)=0\)

\(\Leftrightarrow\left\{{}\begin{matrix}\left(x-2\right)=0\\\left(x-3\right)=0\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}x_1=2\\x_2=3\end{matrix}\right.\)

Answer 2

Lời giải:

\(x^2-5x+6=0\)

\(\Leftrightarrow (x^2-2x)-(3x-6)=0\)

\(\Leftrightarrow x(x-2)-3(x-2)=0\)

\(\Leftrightarrow (x-2)(x-3)=0\Rightarrow \left[\begin{matrix} x=2\\ x=3\end{matrix}\right.\)