已知；x/3=y/4=z/6求；（xy+yz+xz）/(X2+y2+z2)_数学解答

已知；x/3=y/4=z/6求；（xy+yz+xz）/(X2+y2+z2)

人气：366 ℃　时间：2020-03-28 12:41:00

解答

令x/3=y/4=z/6=K
则x=3K,y=4K,c=6K
（xy+yz+xz）/(X2+y2+z2)
=(3K*4K+4K*6K+3K*6K)/(3K*3K+4K*4K+6K*6K)
=54K2/61K2
=54/61