Question

Tìm x biết:
\(|x-3,5|=7,5\) \(|x+\dfrac{4}{5}|\)- \(\dfrac{1}{2}\)= 0 3,6 - \(|x-0,4|=0\)

Answer 1

\(\left|x-3,5\right|=7,5\)

\(\Leftrightarrow x-3,5=7,5\Rightarrow x=11\)

\(\Leftrightarrow x-3,5=-7,5\Rightarrow x=-4\)

\(\left|x+\dfrac{4}{5}\right|-\dfrac{1}{2}=0\)

\(\Leftrightarrow\left|x+\dfrac{4}{5}\right|=\dfrac{1}{2}\)

\(\Leftrightarrow x+\dfrac{4}{5}=\dfrac{1}{2}\Rightarrow x=\dfrac{-3}{10}\)

\(\Leftrightarrow x+\dfrac{4}{5}=-\dfrac{1}{2}\Rightarrow x=\dfrac{-13}{10}\)

\(3,6-\left|x-0,4\right|=0\)

\(\Leftrightarrow\left|x-0,4\right|=3,6\)

\(\Leftrightarrow x-0,4=3,6\Rightarrow x=4\)

\(\Leftrightarrow x-0,4=-3,6\Rightarrow x=-3,2\)