Question

tìm x biết : 

a) x . (x + 2 ) =  0

b) (1/2 + 1/3 - 1/4 ) . ( x - 3 ) = 0

Answer 1

\(a,x\cdot\left(x+2\right)=0\)

\(\Rightarrow\orbr{\begin{cases}x=0\\x+2=0\end{cases}}\)

\(\Rightarrow\orbr{\begin{cases}x=0\\x=0-2\end{cases}}\)

\(\Rightarrow\orbr{\begin{cases}x=0\\x=-2\end{cases}}\)

Answer 2

a)x.(x+2)=0=>x=0 hoặc x+2=0

                  =>x=0 hoặc x=-2

b)7/12 .(x-3)=0

=>x-3=0

=>x=3

Answer 3

Ta có :

a) \(x\left(x+2\right)=0\)

\(\Leftrightarrow\orbr{\begin{cases}x=0\\x+2=0\end{cases}\Leftrightarrow\orbr{\begin{cases}x=0\\x=-2\end{cases}}}\)

Vậy \(x=0\)hoặc \(x=-2\)

b) \(\left(\frac{1}{2}+\frac{1}{3}-\frac{1}{4}\right)\left(x-3\right)=0\)

Vì \(\left(\frac{1}{2}+\frac{1}{3}-\frac{1}{4}\right)\ne0\)

\(\Rightarrow\)\(x-3=0\)

\(\Rightarrow\)\(x=3\)

Vậy \(x=3\)

Answer 4

\(x\cdot\left(x+2\right)=0\)

\(\Rightarrow\orbr{\begin{cases}x=0\\x+2=0\end{cases}}\)

\(\Rightarrow\orbr{\begin{cases}x=0\\x=-2\end{cases}}\)

Vậy x = 0 hoặc - 2