(a²-1/a-1+1)÷a+1+×a²-1/a²+2a,在求值,其中a=2

问题描述:

(a²-1/a-1+1)÷a+1+×a²-1/a²+2a,在求值,其中a=2

原式=[(a+1)(a-1)/(a-1)+1]÷(a+1)×(a+1)(a-1)/a(a+2)
=(a+1+1)/(a+1)×(a+1)(a-1)/a(a+2)
=(a-1)/a
当a=2时,原式=(2-1)/2=1/2