Question

Tìm x:

x. ( x-13 )= 0                                ( x-1 ) . ( 3x - 15) = 0

Answer 1

a) \(x.\left(x-13\right)=0\)

\(\Rightarrow x=0\) hoặc \(x-13=0\)

+) \(x=0\)

+) \(x-13=0\Rightarrow x=13\)

Vậy \(x\in\left\{0;13\right\}\)

b) \(\left(x-1\right).\left(3x-15\right)=0\)

\(\Rightarrow x-1=0\) hoặc \(3x-15=0\)

+) \(x-1=0\Rightarrow x=1\)

+) \(3x-15=0\Rightarrow3x=15\Rightarrow x=5\)

Vậy \(x\in\left\{0;5\right\}\)

Answer 2

\(x\left(x-13\right)=0\)

\(\Leftrightarrow\left[\begin{array}{nghiempt}x=0\\x-13=0\end{array}\right.\)\(\Leftrightarrow\left[\begin{array}{nghiempt}x=0\\x=13\end{array}\right.\)

\(\left(x-1\right)\left(3x-15\right)=0\)

\(\Leftrightarrow\left[\begin{array}{nghiempt}x-1=0\\3x-15=0\end{array}\right.\)\(\Leftrightarrow\left[\begin{array}{nghiempt}x=1\\x=5\end{array}\right.\)