Question

\(\left(\sqrt{1-x}+1\right)\left(\sqrt{1+x}-1\right)=2x\)

Answer 1

\(\left(\sqrt{1-x}+1\right)\left(\sqrt{1+x}-1\right)=0\)

\(\Rightarrow\orbr{\begin{cases}\sqrt{1-x}+1=0\\\sqrt{1+x}-1=0\end{cases}}\)

\(\Rightarrow\orbr{\begin{cases}\sqrt{1-x}=-1\\\sqrt{1+x}=1\end{cases}}\)

Vì \(\sqrt{1-x}\ge0\Rightarrow\sqrt{1-x}\ne-1\)

\(\Rightarrow\sqrt{1+x}=1\)

=>1+x=1

=>x=0

Answer 2

\(\left(\sqrt{1-x}+1\right)\left(\sqrt{1+x}-1\right)=0\)

<=> \(\orbr{\begin{cases}\sqrt{1-x}+1=0\\\sqrt{1+x}-1=0\end{cases}}\)

<=> \(\orbr{\begin{cases}\sqrt{1-x}=-1\left(\text{loại}\right)\\\sqrt{1+x}=1\end{cases}}\)

<=> \(1+x=1\)

<=> \(x=0\)

Answer 3

mình ghi lộn đề