c, \(\left|x+5\right|-6=9\)
\(\left|x+5\right|=9+6\)
\(\left|x+5\right|=15\)
\(x+5=15\) hoặc \(x+5=-15\)
\(x=15-5\) \(x=-15-5\)
\(x=10\) \(x=-20\)
Vậy ...
\(d,2-\left|x-\dfrac{2}{5}\right|=-\dfrac{1}{2}\)
\(\left|x-\dfrac{2}{5}\right|=2+\dfrac{1}{2}\)
\(\left|x-\dfrac{2}{5}\right|=\dfrac{4}{2}+\dfrac{1}{2}\)
\(\left|x-\dfrac{2}{5}\right|=\dfrac{5}{2}\)
\(x-\dfrac{2}{5}=\dfrac{5}{2}\) hoặc \(x-\dfrac{2}{5}=-\dfrac{5}{2}\)
\(x=\dfrac{5}{2}+\dfrac{2}{5}\) \(x=\dfrac{-5}{2}+\dfrac{2}{5}\)
\(x=\dfrac{25}{10}+\dfrac{4}{10}\) \(x=\dfrac{-25}{10}+\dfrac{4}{10}\)
\(x=\dfrac{29}{10}\) \(x=\dfrac{-21}{10}\)
Vậy ...
m, \(2,5:13,5=x:\dfrac{3}{5}\)
\(\dfrac{2,5}{13,5}=\dfrac{x}{\dfrac{3}{5}}\)
\(13,5x=2,5.\dfrac{3}{5}\)
\(13,5x=1,5\)
\(x=1,5:13,5\)
\(x=\dfrac{1}{9}\)
Vậy ..,
k: \(\dfrac{x+2}{3}=\dfrac{x-7}{2}\)
=>\(3\left(x-7\right)=2\left(x+2\right)\)
=>\(3x-21=2x+4\)
=>3x-2x=21+4
=>x=25
