以方程组 {y=2x+2y=−x+1 的解为坐标的点(x,y)在第____象限.
已知a,b,c分别是△ABC的三个内角A,B,C所对的边,若A=45∘,B=60∘,b=3,则a等于( )
— ________does your mother go home?
— She always goes home at half past five.