Giải các phương trình :
a) \(3-4x\left(25-2x\right)=8x^2+x-300\)
b) \(\dfrac{2\left(1-3x\right)}{5}-\dfrac{2+3x}{10}=7-\dfrac{3\left(2x+1\right)}{4}\)
c) \(\dfrac{5x+2}{6}-\dfrac{8x-1}{3}=\dfrac{4x+2}{5}-5\)
d) \(\dfrac{3x+2}{2}-\dfrac{3x+1}{6}=2x+\dfrac{5}{3}\)