Question

Tìm x 

\(8\sqrt{x}=x^2\left(x\ge0\right)\)

Answer 1

8\(\sqrt{x}\)= x^2

bình phương 2 vế, ta được:

64x = x^4

64x - x^4 = 0

x(64 - x³) = 0

x = 0 hoặc x = 4

Answer 2

\(8\sqrt{x}=x^2\)

\(\Leftrightarrow8\sqrt{x}-x^2=0\)

\(\Leftrightarrow\sqrt{x}\left(8-\sqrt{x^3}\right)=0\)

\(\Leftrightarrow\orbr{\begin{cases}\sqrt{x}=0\\8-\sqrt{x^3}=0\end{cases}}\Leftrightarrow\orbr{\begin{cases}x=0\\x=4\end{cases}}\)