1.Tìm x, biết.
a, \(|x|\) + x = \(\dfrac{1}{3}\)
b, \(|x+2|\) = x
c, \(\dfrac{2}{\left(x-1\right)\left(x-3\right)}\) + \(\dfrac{5}{\left(x-3\right)\left(x-8\right)}\) + \(\dfrac{12}{\left(x-8\right)\left(x-20\right)}\) - \(\dfrac{1}{x-20}\) = \(\dfrac{-3}{4}\)
d, \(\dfrac{3}{\left(x+2\right)\left(x+5\right)}\) + \(\dfrac{5}{\left(x+5\right)\left(x+10\right)}\) + \(\dfrac{7}{\left(x+10\right)\left(x+17\right)}\) = \(\dfrac{x}{\left(x+2\right)\left(x+17\right)}\)
e, \(\dfrac{x-1}{2009}\) + \(\dfrac{x-2}{2008}\) = \(\dfrac{x-3}{20007}\) + \(\dfrac{x-4}{2006}\)