⊙O的半径为10cm,两平行弦AC,BD的长分别为12cm,16cm,则两弦间的距离是____________.
若单项式与的差仍是单项式,则m﹣2n= ______.
若单项式2xmy3与﹣3xy3n是同类项,则m﹣n=______.
若x3yn与2xmy是同类项,则m+2n=______.
若﹣7xm+2y2与﹣3x3yn是同类项,则m﹣n=______.
已知x5yn与﹣3x2m+1y3n﹣2是同类项,则m+n=______.