初三数学,先化简,再求值

2025-01-26 08:43:13
推荐回答(2个)
回答1:

[(5/(a-2))-a-2]=(3+a)(3-a)/(a-2)
消除同类项可知 原式等于
(-1)/2(3+a)=(-1)/2√3=-√3/6
望采纳

回答2:

[(a-3)/(2a-4) ]÷[5/(a-2)-a-2]
=[(a-3)/2(a-2)]÷[5/(a-2)-(a+2)]
=[(a-3)/2(a-2)]÷[5/(a-2)-(a+2)x(a-2)/(a-2)]
=[(a-3)/2(a-2)]÷[(5-aa+4)/(a-2)]
=[(a-3)/2(a-2)]x[(a-2)/(a+3)(3-a)]
=-1/[2(a+3)]
其中a=√3-3,
-1/[2(a+3)]==-1/[2√3]=-√3/6