cậu gì ơi , cho tớ đề bài được không
Bài 1 :
a) x3 -25x = 0
x(x2 - 25 ) = 0
x(x - 5 ) ( x + 5 ) = 0
\(\Rightarrow\left[{}\begin{matrix}x=0\\x-5=0\\x+5=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=0\\x=5\\x=-5\end{matrix}\right.\)
b) \(4x^2-9-x\left(2x-3\right)=0\)
\(\left(2x-3\right)\left(2x+3\right)-x\left(2x-3\right)=0\)
\(\left(2x-3\right)\left(2x+3-x\right)=0\)
\(\left(2x-3\right)\left(x+3\right)=9\)
\(\Rightarrow\left[{}\begin{matrix}2x-3=0\\x+3=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=\frac{3}{2}\\x=-3\end{matrix}\right.\)
