Question

Answer 1

giúp em bài 2 với ạ

 

Answer 2

Bài 2:

a) ĐKXĐ: \(a\ge0,a\ne1\)

b) \(M=\left[\dfrac{\sqrt{a}\left(\sqrt{a}+1\right)}{\sqrt{a}+1}+1\right]\left[1+\dfrac{-\sqrt{a}\left(1-\sqrt{a}\right)}{1-\sqrt{2}}\right]\)

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

Answer 3

Bài 3: 

a: \(\Leftrightarrow\sqrt{2-x}=4\)

\(\Leftrightarrow2-x=16\)

hay x=-14

b: \(\Leftrightarrow\left|x-2\right|=5\)

\(\Leftrightarrow\left[{}\begin{matrix}x-2=5\\x-2=-5\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=7\\x=-3\end{matrix}\right.\)