Question

Tìm x:
a)(x-6)(x+6)=64
b)x²-4x+3=0

Answer 1

a) \(\Leftrightarrow x^2-36=64\)

\(\Leftrightarrow x^2=100\)

\(\Leftrightarrow x=\pm10\)

Vậy \(x=\pm10\)

b) \(\Leftrightarrow x^2-x-3x+3=0\)

\(\Leftrightarrow x\left(x-1\right)-3\left(x-1\right)=0\)

\(\Leftrightarrow\left(x-1\right)\left(x-3\right)=0\)

\(\Leftrightarrow\left[{}\begin{matrix}x-1=0\\x-3=0\end{matrix}\right.\) \(\Leftrightarrow\left[{}\begin{matrix}x=1\\x=3\end{matrix}\right.\)

Vậy \(x\in\left\{1;3\right\}\)