a: \(\Leftrightarrow\dfrac{2\left(2x+3\right)}{4x-6}-\dfrac{3}{4x-6}=\dfrac{2}{5}\)
\(\Leftrightarrow\dfrac{5\left(4x+6-3\right)}{5\left(4x-6\right)}=\dfrac{2\left(4x-6\right)}{5\left(4x-6\right)}\)
=>5(4x+3)=2(4x-6)
=>20x+15=8x-12
=>12x=-27
hay x=-9/4
b: \(\Leftrightarrow\dfrac{x+29}{31}+1-\dfrac{x+27}{33}-1=\dfrac{x+17}{43}+1-\dfrac{x+15}{45}-1\)
\(\Leftrightarrow\left(x+60\right)\left(\dfrac{1}{31}-\dfrac{1}{33}-\dfrac{1}{43}+\dfrac{1}{45}\right)=0\)
=>x+60=0
hay x=-60