a, x(x+3)=0
=>x hoặc x+3=0
=>x+3=0
=>x=0-3
=>x=-3
=>x= 0 hoặc x=-3
b, (x-2)(5-x)=0
=>x-2 hoặc 5-x=0
=>x= 0+2 hoặc x= 5-0
=>x= 2 hoặc x= 5
c, (x-1)(x2+1)=0
=>x-1 hoặc x2-1=0
=>x=1 ->(1)
x2-1=0
=>x2=1
=>x=1
Vậy x=1
a) x(x+3)=0
=>x=0 hoặc x+3=0
x=-3
Vậy x=0; x=-3
b)(x-2)(5-x)=0
=>x-2=0 hoặc 5-x=0
x=2 x=5
Vậy x=2; x=5
c)(x-1)(x2+1)=0
=>x-1=0 hoặc x2+1=0
x=1 x2=-1(vô lí)
Vậy x=1
a)\(x\left(x+3\right)=0\)
\(\Leftrightarrow\left[\begin{array}{nghiempt}x=0\\x+3=0\end{array}\right.\)\(\Leftrightarrow\left[\begin{array}{nghiempt}x=0\\x=-3\end{array}\right.\)
b)\(\left(x-2\right)\left(5-x\right)=0\)
\(\Leftrightarrow\left[\begin{array}{nghiempt}x-2=0\\5-x=0\end{array}\right.\)\(\Leftrightarrow\left[\begin{array}{nghiempt}x=2\\x=5\end{array}\right.\)
c)\(\left(x-1\right)\left(x^2+1\right)=0\)
\(\Leftrightarrow x-1=0\) (vì \(x^2+1>0\))
\(\Leftrightarrow x=1\)
a) \(x\left(x+3\right)=0\)
\(\Leftrightarrow\begin{cases}x=0\\x+3=0\end{cases}\)
\(\Rightarrow\begin{cases}x=0\\x=-3\end{cases}\)
b) \(\left(x-2\right)\left(5-x\right)=0\)
\(\Leftrightarrow\begin{cases}x-2=0\\5-x=0\end{cases}\)
\(\Rightarrow\begin{cases}x=2\\x=5\end{cases}\)
c) \(\left(x-1\right)\left(x^2+1\right)=0\)
\(\Leftrightarrow x-1=0\)
\(\Rightarrow x=1\)