Question

\(\left(3^x-27\right)\left(2\sqrt{x}-4\right)=0\)

giúp em với ạ

Answer 1

\(\left(3^x-27\right)\left(2\sqrt{x}-4\right)=0\)

\(\Rightarrow\left[{}\begin{matrix}3^x-27=0\\2\sqrt{x}-4=0\end{matrix}\right.\)

\(\Rightarrow\left[{}\begin{matrix}3x=27\\2\sqrt{x}=4\end{matrix}\right.\)

\(\Rightarrow\left[{}\begin{matrix}3x=3^3\\\sqrt{x}=2\end{matrix}\right.\)

\(\Rightarrow\left[{}\begin{matrix}x=3\\\left(\sqrt{x}\right)^2=2^2\end{matrix}\right.\)

\(\Rightarrow\left[{}\begin{matrix}x=3\\x=4\end{matrix}\right.\)

Vậy \(x=3;x=4\)

Answer 2

\(=>\left[{}\begin{matrix}3^x-27=0\\2.\sqrt{x}-4=0\end{matrix}\right.\)

\(=>\left[{}\begin{matrix}3^x=0+27\\2.\sqrt{x}=0+4\end{matrix}\right.\)

\(=>\left[{}\begin{matrix}3^x=27\\2.\sqrt{x}=4\end{matrix}\right.\)

\(=>\left[{}\begin{matrix}3^x=3^3\\\sqrt{x}=4:2\end{matrix}\right.\)

\(=>\left[{}\begin{matrix}x=3\\\sqrt{x}=2\end{matrix}\right.\)

\(=>\left[{}\begin{matrix}x=3\\x=4\end{matrix}\right.\)

Vậy .....

Answer 3

3^x — 27 = 0 và 2√x - 4 = 0

<=> 3^x = 27 và 2√x = 4

<=> x = 3 và x = 4