题目内容
若
=
=
,求
的值.
| x |
| 2 |
| y |
| 3 |
| z |
| -5 |
| 2x+y+3z |
| 2x |
设
=
=
=k,则x=2k,y=3k,z=-5k;
所以
=
=
=-2.
| x |
| 2 |
| y |
| 3 |
| z |
| -5 |
所以
| 2x+y+3z |
| 2x |
| 2×2k+3k+3×(-5) |
| 2×2k |
| -8k |
| 4k |
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