3x - 2m + 1 = 0
3x = 2m - 1
x = (2m - 1)/3
2 - m = 2x
x = (2 - m)/2
因为解相等
所以 (2m - 1)/3 = (2 - m)/2
2(2m - 1) = 3(2 - m)
4m - 2 = 6 - 3m
7m = 8
m = 8/7
把 m = 8/7 代入 x = (2m - 1)/3 得:
x = 3/7