发布网友
共2个回答
热心网友
令x/3=y/4=z/5=k;
则x=3k,y=4k,z=5k;
(xy+yz+xz)/(xx+yy+zz)=(3k*4k+4k*5k+3k*5k)/(3k*3k+4k*4k+5k*5k)=(12+20+15)/(9+16+25)=47/50
热心网友
设x/3=y/4=z/5=k得47/50