Giải các phương trình sau:
a)\(\left|x^2-3x-5\right|+2\left|2x-1\right|=x^2-4\)
b)\(\frac{4}{2x+1}+\frac{3}{2x+2}=\frac{2}{2x+3}+\frac{1}{2x+4}\)
c)\(\frac{2x-5}{2x^2+3x-5}+\frac{3x+1}{1-x}=\frac{x+20}{4x+10}\)
d)\(\frac{1}{x^2+5x+4}+\frac{1}{x^2+11x+28}+\frac{1}{x^2+17x+70}=\frac{3}{4x-2}\)