Question

Tìm x:

x^4-17x^2=0

Answer 1

\(x^4-17x^2=0\)

\(\Rightarrow x^2.\left(x^2-17\right)=0\)

\(\Rightarrow\left[{}\begin{matrix}x^2=0\\x^2-17=0\end{matrix}\right.\)

\(\Rightarrow\left[{}\begin{matrix}x=0\\x^2=17\end{matrix}\right.\)

\(\Rightarrow\left[{}\begin{matrix}x=0\\x=\pm\sqrt{17}\end{matrix}\right.\)

Vậy .........................

Answer 2

\(x^4-17x^2=0\)

\(\Leftrightarrow x^2\left(x^2-17\right)=0\)

\(\Leftrightarrow x^2=17\)

\(\Leftrightarrow x=\pm\sqrt{17}\)

Answer 3

x^4-17x^2=0

x^2 . (x^2-17) = 0

=> x^2 = 0 hoặc x^2-17=0

+) x = 0 +) x^2 = 17

x = \(\sqrt{17}\)

Vậy x \(\in\) {0;\(\sqrt{17}\)}