计算:1/(a+3)+2a/(a-1)-(3a+5)/(a^2+2a-3)

问题描述:

计算:1/(a+3)+2a/(a-1)-(3a+5)/(a^2+2a-3)

原式=(a-1)/(a+3)(a-1)+2a(a+3)/(a+3)(a-1)-(3a+5)/(a+3)(a-1)
=(a-1+2a²+6a-3a-5)/(a+3)(a-1)
=(2a²-2a-6)/(a²+2a-3)