\(\left(x-2\right)\left(4x+5\right)=0\\ \Leftrightarrow\left[{}\begin{matrix}x-2=0\\4x+5=0\end{matrix}\right.\\ \Leftrightarrow\left[{}\begin{matrix}x=2\\x=-\frac{5}{4}\end{matrix}\right.\\ \Rightarrow S=\left\{-\frac{5}{4};2\right\}\)
x-2=0 hoặc 4x+5=0
x=2 hoặc x=\(\frac{-5}{4}\)
( x - 2 ) ( 4x + 5 ) = 0
➜\(\left[{}\begin{matrix}x-2=0\\4x+5=0\end{matrix}\right.\)
➜\(\left[{}\begin{matrix}x=2\\4x=-5\end{matrix}\right.\)
➜\(\left[{}\begin{matrix}x=2\\x=\frac{-5}{4}\end{matrix}\right.\)
Vậy S∈\(\left\{2;\frac{-5}{4}\right\}\)
\(\left(x-2\right)\left(4x+5\right)=0\)
\(\left[{}\begin{matrix}x-2=0\\4x+5=0\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=2\\x=\frac{-5}{4}\end{matrix}\right.\)
Người gởi bài có phúc
(x-2)(4x+5)=0
⇔x-2=0 hoặc 4x+5=0
⇔x=2 hoặc x=-5/4
Vậy ...
