Question

Giúp mình với ạ

( -2x + 5/2 ) . ( x^2 + 4 ) = 0

Answer 1

\(\left(-2x+\dfrac{5}{2}\right)\left(x^2+4\right)=0\)
\(\Rightarrow\left[{}\begin{matrix}-2x+\dfrac{5}{2}=0\\x^2+4=0\end{matrix}\right.\)            \(\Rightarrow\left[{}\begin{matrix}-2x=\dfrac{-5}{2}\\x^2=-4\end{matrix}\right.\)
\(\Rightarrow\left[{}\begin{matrix}x=\dfrac{5}{4}\\\left(vô.lý\right)\end{matrix}\right.\)            Vậy \(x=\dfrac{5}{4}\)

Answer 2

(-2x + 5/2).(x² + 4) = 0

-2x + 5/2 = 0 (do x² + 4 > 0)

-2x = -5/2

x = -5/2 : 2

x = -5/4