Question

x² - 4 = 5 

        Nhanh nhé

Answer 1

\(x^2-4=5\\ \Rightarrow x^2=9\\ \Rightarrow\left[{}\begin{matrix}x=3\\x=-3\end{matrix}\right.\)

Vậy \(x\in\left\{3;-3\right\}\)

Answer 2

Ta có: \(x^2-4=5\)

\(\Leftrightarrow x^2=9\)

hay \(x\in\left\{3;-3\right\}\)

Vậy: \(x\in\left\{3;-3\right\}\)

Answer 3

x^2 -4=5

<=> x^2= 5-4

<=> x^2=1=1^2

=>x=1

mũ hai mk k vt đc nên vt ^2 nha