Question

Answer 1

a: |x|=20

=>x=20 hoặc x=-20

b: |3-x|=0,5

=>|x-3|=0,5

=>x-3=0,5 hoặc x-3=-0,5

=>x=3,5 hoặc x=2,5

c: \(\left|x-\sqrt{2}\right|=0\)

=>\(x-\sqrt{2}=0\)

=>\(x=\sqrt{2}\)

d: \(\left|-x\right|=\sqrt{11}\)

=>\(\left|x\right|=\sqrt{11}\)

=>\(x=\pm\sqrt{11}\)

Answer 2

a) \(\left|x\right|=20\)

\(\Leftrightarrow\left[{}\begin{matrix}x=20\\x=-20\end{matrix}\right.\)

b) \(\left|3-x\right|=0,5\)

\(\Leftrightarrow\left[{}\begin{matrix}3-x=0,5\\3-x=-0,5\end{matrix}\right.\)

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

c) \(\left|x-\sqrt[]{2}\right|=0\)

\(\Leftrightarrow x-\sqrt[]{2}=0\)

\(\Leftrightarrow x=\sqrt[]{2}\)

d) \(\left|-x\right|=\sqrt[]{11}\)

\(\Leftrightarrow\left[{}\begin{matrix}-x=\sqrt[]{11}\\-x=-\sqrt[]{11}\end{matrix}\right.\)

\(\Leftrightarrow\left[{}\begin{matrix}x=-\sqrt[]{11}\\x=\sqrt[]{11}\end{matrix}\right.\)