Question

已知

x

3

=

y

4

=

z

6

≠0，求

x+y-z

x-y+z

的值．

Answer 1

分析：首先设

x

3

=

y

4

=

z

6

=k，即可得x=3k，y=4k，z=6k，然后将其代入

x+y-z

x-y+z

，化简即可求得

x+y-z

x-y+z

的值．

解答：解：设

x

3

=

y

4

=

z

6

=k，
则x=3k，y=4k，z=6k，
∴

x+y-z

x-y+z

=

3k+4k-6k

3k-4k+6k

=

1

5

．

点评：此题考查了比例的性质．此题比较简单，注意设

x

3

=

y

4

=

z

6

=k是解此题的关键．