Question

已知：关于x，y的方程组4x-3y=2m，x+2y=2-m的解x＞y，求m的值

Answer 1

4x-3y=2m (1)
x+2y=2-m (2)
(1)×3-(2)
12x-9y-x-2y=6m-2+m
11x-11y=7m-2

x>y则x-y>0
所以11x-11y>0
所以7m-2>0
m>2/7

Answer 2

4x-3y=2m，
x+2y=2-m
上式-下式x4
-11y=2m-4*(2-m)=6m-8
y=(8-6m)/11
x=2-m-2y=2-m-2*(8-6m)/11=[22-11m-(16-12m)]/11=(6+m)/11
x＞y
(6+m)/11＞(8-6m)/11
6+m＞8-6m
m＞2/7

Answer 3

4X-3Y=6 =》两边同时乘以2/3 6x-9/2Y=9
6X+MY=26 两式相减 (M-9/2)Y=17 因为有整数解则
17/(M-9/2)为整数 则m为21.5