Bài 2:
1: \(x+\dfrac{5}{7}=\dfrac{2}{7}\)
=>\(x=\dfrac{2}{7}-\dfrac{5}{7}\)
=>\(x=-\dfrac{3}{7}\)
2: \(x-3\dfrac{2}{5}=1\dfrac{1}{5}\)
=>\(x-\dfrac{17}{5}=\dfrac{6}{5}\)
=>\(x=\dfrac{6}{5}+\dfrac{17}{5}=\dfrac{23}{5}\)
3: \(\dfrac{2}{3}\cdot x-\dfrac{4}{5}=-\dfrac{3}{10}\)
=>\(\dfrac{2}{3}\cdot x=-\dfrac{3}{10}+\dfrac{4}{5}=\dfrac{8}{10}-\dfrac{3}{10}=\dfrac{1}{2}\)
=>\(x=\dfrac{1}{2}:\dfrac{2}{3}=\dfrac{3}{4}\)
4: \(\left(3\dfrac{1}{2}+2x\right)\cdot2\dfrac{2}{3}=5\dfrac{1}{3}\)
=>\(\left(2x+\dfrac{7}{2}\right)\cdot\dfrac{8}{3}=\dfrac{16}{3}\)
=>\(2x+\dfrac{7}{2}=2\)
=>2x=-3/2
=>x=-3/4
5: \(\dfrac{2}{5}\cdot x-\dfrac{1}{2}=\dfrac{3}{7}\)
=>\(\dfrac{2}{5}\cdot x=\dfrac{3}{7}+\dfrac{1}{2}=\dfrac{13}{14}\)
=>\(x=\dfrac{13}{14}:\dfrac{2}{5}=\dfrac{13}{14}\cdot\dfrac{5}{2}=\dfrac{65}{28}\)
6: \(\left(\dfrac{3}{5}+x\right)\cdot\dfrac{2}{3}=1\dfrac{7}{15}\)
=>\(\left(x+\dfrac{3}{5}\right)\cdot\dfrac{2}{3}=\dfrac{22}{15}\)
=>\(x+\dfrac{3}{5}=\dfrac{22}{15}:\dfrac{2}{3}=\dfrac{22}{15}\cdot\dfrac{3}{2}=\dfrac{11}{5}\)
=>x=11/5-3/5=8/5
