Giải phương trình:
a, \(\frac{x+1}{x+2}\)+ \(\frac{5}{x-2}\)= \(\frac{4}{x^2}\)khác 1
b,\(\frac{x-1}{x+2}\)-\(\frac{x+1}{x^2+x+1}\)=\(\frac{10}{x\cdot\left(x^4+x^2+1\right)}\)
c, \(\frac{x+9}{10}\)+\(\frac{x+10}{9}\)= \(\frac{9}{x+10}\)+ \(\frac{10}{x+9}\)
d,\(\frac{x^2-2\cdot x+2}{x-1}\)+\(\frac{x^2-8\cdot x+20}{x-4}\)= \(\frac{x^2-4\cdot x+6}{x-2}\)+ \(\frac{x^2-6\cdot x+12}{x-3}\)