问题
选择题
若
|
答案
∵
=x 2
=y 7
,设x=2a,y=7a,z=5a,z 5
∴A=
=y x+y+z
=7a 2a+7a+5a
,1 2
B=
=x+z y
=1,2a+5a 7a
C=
=x+y-z x
=2.2a+7a-5a 2a
∴A<B<C.
故选:B.
若
|
∵
=x 2
=y 7
,设x=2a,y=7a,z=5a,z 5
∴A=
=y x+y+z
=7a 2a+7a+5a
,1 2
B=
=x+z y
=1,2a+5a 7a
C=
=x+y-z x
=2.2a+7a-5a 2a
∴A<B<C.
故选:B.