问题 填空题
x
3
=
y
4
=
z
5
,则
-x+y
x+2y+3z
=______.
答案

x
3
=
y
4
=
z
5
=k,

则x=3k,y=4k,z=5k,

所以

-x+y
x+2y+3z
=
-3k+4k
3k+2×4k+3×5k
=
1
26

故答案为:

1
26

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