Question

Tìm x 
x(x-5)-4x+20=0

Answer 1

\(x\left(x-5\right)-4x+20=0\)

\(x\left(x-5\right)-4\left(x-5\right)=0\)

\(\left(x-4\right)\left(x-5\right)=0\)

\(\Rightarrow\orbr{\begin{cases}x-4=0\\x-5=0\end{cases}}\)

\(\Rightarrow\orbr{\begin{cases}x=4\\x=5\end{cases}}\)

Answer 2

x(x-5)-4x+20=0

 x(x-5)-4(x-5)=0

      (x-5)(x-4)=0

   =>   \(\orbr{\begin{cases}x-5=0\\x-4=0\end{cases}}\)

=>\(\orbr{\begin{cases}x=5\\x=4\end{cases}}\)

Vậy ..........

#Hok tốt#^v^