Question

(x2-9).(3-5.x)=0

Answer 1

\(\left(x.2-9\right).\left(3-5.x\right)=0\)

\(\Rightarrow\orbr{\begin{cases}x.2-9=0\\3-5.x=0\end{cases}\Rightarrow}\orbr{\begin{cases}x.2=0+9\\5.x=3-0\end{cases}\Rightarrow\orbr{\begin{cases}x.2=9\\5.x=3\end{cases}}}\)

\(\Rightarrow\orbr{\begin{cases}x=9:2\\x=3:5\end{cases}\Rightarrow}\orbr{\begin{cases}x=\frac{9}{2}\\x=\frac{3}{5}\end{cases}}\)

Vậy ...........................

Answer 2

Bài như thế này à ???

\((x^2-9)(3-5x)=0\)

\(\Rightarrow\orbr{\begin{cases}x^2-9=0\\3-5x=0\end{cases}}\)

\(\Rightarrow\orbr{\begin{cases}x^2=9\\5x=3\end{cases}}\)

\(\Rightarrow\orbr{\begin{cases}x=\pm3\\x=\frac{3}{5}\end{cases}}\)