—Next week.
A:where has your brother gone
B:when your brother will come back
C:how your brother goes to school
D:why your brother went to Shanghai
如图所示,直线L1的解析式是y=2x﹣1,直线L2的解析式是y=x+1,则方程组 x-y=-12x-y=1的解是____ .