先化简,再求值:(a/a-2)-(2a/a²-2a)-2/a,其中a=3/2.
问题描述:
先化简,再求值:(a/a-2)-(2a/a²-2a)-2/a,其中a=3/2.
答
原式=(a²-2a-2a+4)/a(a-2)
=(a²-4a+4)/a(a-2)
=(a-2)²/a(a-2)
=(a-2)/a
=(3/2-2)/(3/2)
=-1/2*2/3
=-1/3