A:good luck with your tri
B:take it easy
C:it certainly will be happy
D:make yourself comfortable
设y=kx+b,且当x=1时,y=1;当x=2时,y=-4,则k、b的值依次为( )
如图,将△ABC的三边分别扩大一倍得到△A1B1C1(顶点均在格点上),若它们是以P点为位似中心的位似图形,则P点的坐标是( ).
计算: