a)\(x-\dfrac{5x+2}{6}=\dfrac{7-3x}{4}\)
\(\Leftrightarrow\dfrac{12x-10x-4}{12}=\dfrac{21-9x}{12}\)
\(\Leftrightarrow2x-4=21-9x\)
\(\Leftrightarrow2x-4-21+9x=0\)
\(\Leftrightarrow11x-25=0\)
\(\Leftrightarrow x=\dfrac{25}{11}\)
b)\(\dfrac{10x+3}{12}=1+\dfrac{6+8x}{9}\)
\(\Leftrightarrow\dfrac{30x+9}{36}=\dfrac{36+24+32x}{36}\)
\(\Leftrightarrow30x+9=60+32x\)
\(\Leftrightarrow30x+9-60-32x=0\)
\(\Leftrightarrow-2x-51=0\)
\(\Leftrightarrow x=-\dfrac{51}{2}\)
c)\(\dfrac{x}{3}-\dfrac{2x+1}{2}=\dfrac{x}{6}-6\)
\(\Leftrightarrow\dfrac{2x-6x-3}{6}=\dfrac{x-36}{6}\)
\(\Leftrightarrow-4x-3=x-36\)
\(\Leftrightarrow-4x-3-x+36=0\)
\(\Leftrightarrow-5x+33=0\)
\(\Leftrightarrow x=\dfrac{33}{5}\)
d)\(\dfrac{2+x}{3}-\dfrac{1}{2}x=\dfrac{1-2x}{4}+\dfrac{1}{4}\)
\(\Leftrightarrow\dfrac{8+4x-6x}{12}=\dfrac{3-6x+3}{12}\)
\(\Leftrightarrow8-2x=6-6x\)
\(\Leftrightarrow8-2x-6+6x=0\)
\(\Leftrightarrow4x+2=0\)
\(\Leftrightarrow x=-\dfrac{1}{2}\)
Tính lại xem đúng không nha 
a) \(x-\dfrac{5x+2}{6}=\dfrac{7-3x}{4}\)
\(\Leftrightarrow\dfrac{24x}{24}-\dfrac{4\left(5x+2\right)}{24}=\dfrac{6\left(7-3x\right)}{24}\)
\(\Leftrightarrow24x-4\left(5x+2\right)=6\left(7-3x\right)\)
\(\Leftrightarrow24x-20x-8=42-18x\)
\(\Leftrightarrow4x-8=42-18x\)
\(\Leftrightarrow4x+18x=42+8\)
\(\Leftrightarrow22x=50\)
\(\Leftrightarrow x=\dfrac{25}{11}\)
Vậy S\(=\left\{\dfrac{25}{11}\right\}\)
