先化简,再求值:(1+3/a-2)÷a+1/a²-4,其中a=3/2
问题描述:
先化简,再求值:(1+3/a-2)÷a+1/a²-4,其中a=3/2
答
∵a=3/2
∴[1+3/(a-2)]÷[(a+1)/(a²-4)]
=(a+1)/(a-2)×[(a+2)(a-2)/(a+1)]
=a+2
=3/2+2
=3.5