直角三角形边长度为5,12,则斜边上的高( )
A:6
B:8
C:1813
D:6013
如果方程组2x+3y=75x-y=9的解是方程3x+my=8的一个解,则m=( )
—Let's give her some books __________ her birthday.
—That's a good idea!