Question

Tìm x : (x-2).(x+4)=0

Answer 1

\(\left(x-2\right).\left(x+4\right)=0\)

\(\Leftrightarrow\left[\begin{array}{nghiempt}x-2=0\\x+4=0\end{array}\right.\)

\(\Leftrightarrow\left[\begin{array}{nghiempt}x=2\\x=-4\end{array}\right.\)

Vậy \(x\in\left\{2;-4\right\}\)

Answer 2

(x - 2) (x + 4) = 0

=> x - 2 = 0 hoặc x + 4 = 0

=> x = 2 hoặc x = -4

Answer 3

( x - 2 ).( x+4 ) = 0 

\(\Rightarrow\) x - 2 = 0 hoặc x + 4 = 0

+) x - 2 = 0

           x = 0 + 2 

           x = 2

+) x + 4 = 0

           x = 0 - 4 

           x = -4

Vậy x = 2 hoặc x = -4

Answer 4

(x-2).(x+4)=0

x-2=0          x=0+2                     x= 2

x+4=0        x =0-4                   x= -4

 

 

Answer 5

\(\left(x-2\right).\left(x+4\right)=0\)

\(\Leftrightarrow\left[\begin{array}{nghiempt}\left(x-2\right)=0\\\left(x+4\right)=0\end{array}\right.\)

\(\Leftrightarrow\left[\begin{array}{nghiempt}x=0+4\\x=0-4\end{array}\right.\)

\(\Leftrightarrow\left[\begin{array}{nghiempt}x=2\\x=-4\end{array}\right.\)

Vậy:  \(\left[\begin{array}{nghiempt}x=2\\x=-4\end{array}\right.\)