已知a/2=b/3=c/4=k（k不等于0）球a²-ab+ac/a-b-c*2/a-b+c的值

已知a/2=b/3=c/4=k（k不等于0）球a²-ab+ac/a-b-c*2/a-b+c的值

a=2k b=3k c=4k 带入题目即可求

a=2k，b=3k，c=4k
a²-ab+ac/a-b-c*2/a-b+c
=[a（a-b+c）/（a-b-c）][2/(a-b+c)]
=2a/(a-b-c)
=4k/(2k-3k-4k)
=4k/(-5k)
=-4/5