平面直角坐标系中,点P(3,1-a)与点Q(b+2,3)关于原点对称,则a+b=________. 答案:【答案】﹣1【解析】根据关于原点对称的点,横坐标与纵坐标都互为相反数解答.∵点P(3,1-a)与点Q(b+2,3)关于原点对称,∴3=-(b+2),1-a=-3,解得:a=4,b=-5,∴a+b=-1.故答案为:-1.— Would you like to go for a picnic to enjoy the fresh
air outside this weekend?
— __________. It will be a sunny day.
A.I’d love to B.Don’t mention it
C.No, I won’t D.It doesn’t matter