Question

tìm x

-X^2+25X=0

Answer 1

\(-x^2+25x=0\)

\(\Rightarrow x\left(-x+25\right)=0\)

\(\Rightarrow\orbr{\begin{cases}x=0\\-x+25=0\end{cases}\Rightarrow\orbr{\begin{cases}x=0\\x=25\end{cases}}}\)

Answer 2

\(-x^2+25x=0\)

\(\Leftrightarrow-\left(x^2-25\right)=0\)

\(\Leftrightarrow-\left(x-5\right)\left(x+5\right)=0\)

\(\Leftrightarrow\orbr{\begin{cases}x-5=0\\x+5=0\end{cases}\Leftrightarrow\orbr{\begin{cases}x=5\\x=-5\end{cases}}}\)