sau bạn đăng tách ra cho mn cùng giúp nhé
1, \(x+\dfrac{5}{3}=\dfrac{1}{81}\Leftrightarrow x=\dfrac{1}{81}-\dfrac{5}{3}=-\dfrac{134}{81}\)
2, \(x-\dfrac{1}{5}=2\Leftrightarrow x=2+\dfrac{1}{5}=\dfrac{11}{5}\)
3, \(x-\dfrac{4}{5}=-\dfrac{3}{10}\Leftrightarrow x=-\dfrac{3}{10}+\dfrac{4}{5}=\dfrac{5}{10}=\dfrac{1}{2}\)
16,đk x khác 5;-2 \(\dfrac{3}{x-5}=-\dfrac{4}{x+2}\Rightarrow3x+6=-4x+20\Leftrightarrow7x=14\Leftrightarrow x=2\)(tm)
17, đk : x khác -3
\(\dfrac{x+3}{-4}=-\dfrac{9}{x+3}\Rightarrow\left(x+3\right)^2=36\)
TH1 : x + 3 = 6 <=> x = 3 (tm)
TH2 : x + 3 = -6 <=> x = -9 (tm)
18,
\(\dfrac{3}{x-5}=\dfrac{-4}{x+2}\\ 3\left(x+2\right)=-4\left(x-5\right)\\ 3x+6=-4x+20\\ 3x+4x=-6+20\\ 7x=14\\ x=2\)
19,
\(\left(2,4x-36\right):1\dfrac{5}{7}=-1\\ \left(2,4x-36\right):\dfrac{12}{7}=-1\\ \left(2,4x-36\right)=\left(-1\right).\dfrac{12}{7}\\ 2,4x-36=\dfrac{-12}{7}\\ 2,4x=\dfrac{-12}{7}+36\\ 2,4x=\dfrac{240}{7}\\ x=\dfrac{100}{7}\)
20,
\(\left(3\dfrac{4}{5}-2x\right).1\dfrac{1}{3}=5\dfrac{5}{7}\\ \left(\dfrac{19}{5}-2x\right).\dfrac{4}{3}=\dfrac{40}{7}\\ \left(\dfrac{19}{5}-2x\right)=\dfrac{40}{7}:\dfrac{4}{3}\\ \dfrac{19}{5}-2x=\dfrac{30}{7}\\ -2x=\dfrac{30}{7}-\dfrac{19}{5}\\ -2x=\dfrac{17}{35}\\ x=\dfrac{-17}{70}\)
