Question

tìm x biết

Answer 1

=>x^2=9/4

=>x^2=(3/2)^2

=>x=3/2 hoặc x=-3/2

Answer 2

\(x^2=\dfrac{-9}{-4}=\dfrac{9}{4}\\ \Leftrightarrow\left[{}\begin{matrix}x^2=\left(\dfrac{3}{2}\right)^2\\x^2=\left(-\dfrac{3}{2}\right)^2\end{matrix}\right.\\ \Leftrightarrow x=\pm\dfrac{3}{2}\)

Answer 3

Có: x² = \(\dfrac{-9}{-4}\) 

=> x² = \(\left(\dfrac{3}{2}\right)^2\)=\(\left(-\dfrac{3}{2}\right)^2\)

=> x ∈ { 3/2;-3/2}

Vậy