a: \(-\dfrac{2}{5}+\dfrac{3}{5}x=\dfrac{1}{10}-\dfrac{-3}{5}\)
=>\(\dfrac{3}{5}x=\dfrac{1}{10}+\dfrac{3}{5}+\dfrac{2}{5}=\dfrac{1}{10}+1=\dfrac{11}{10}\)
=>\(x=\dfrac{11}{10}:\dfrac{3}{5}=\dfrac{11}{10}\cdot\dfrac{5}{3}=\dfrac{11}{6}\)
b: \(\left(\dfrac{2}{7}x+\dfrac{3}{7}\right):\dfrac{17}{7}+\dfrac{4}{7}=1\)
=>\(\left(\dfrac{2}{7}x+\dfrac{3}{7}\right):\dfrac{17}{7}=\dfrac{3}{7}\)
=>\(\dfrac{2}{7}x+\dfrac{3}{7}=\dfrac{3}{7}\cdot\dfrac{17}{7}=\dfrac{51}{49}\)
=>\(\dfrac{2}{7}x=\dfrac{51}{49}-\dfrac{3}{7}=\dfrac{30}{49}\)
=>\(x=\dfrac{30}{49}:\dfrac{2}{7}=\dfrac{30}{49}\cdot\dfrac{7}{2}=\dfrac{15}{7}\)
c: \(50\%\cdot x-1,2:0,3=0,4\)
=>0,5*x-4=0,4
=>0,5x=4,4
=>x=4,4:0,5=8,8
d: 25%-1/2(1-x)=0,5
=>\(0,25x-0,5+0,5x=0,5\)
=>0,75x=1
=>\(x=\dfrac{1}{0,75}=\dfrac{4}{3}\)
