已知4x-3y-6z=0x+2y-7z=0,则x-y+zx+y+z=______.-数学

题目简介

已知4x-3y-6z=0x+2y-7z=0,则x-y+zx+y+z=______.-数学

题目详情

已知
4x-3y-6z=0
x+2y-7z=0
,则
x-y+z
x+y+z
=______.
题型:解答题难度:中档来源:不详

答案

4x-3y-6z=0①
x+2y-7z=0②

①×7-②×6得:2x-3y=0,
解得:x=class="stub"3
2
y,
①×2+②×3得:11x-33z=0
解得:x=3z,
∵x=class="stub"3
2
y,x=3z,
∴y=2z,
class="stub"x-y+z
x+y+z
=class="stub"3z-2z+z
3z+2z+z
=class="stub"2z
6z
=class="stub"1
3

故答案为:class="stub"1
3

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