若方程x2-5x=0的一个根是a,则a2-5a+2的值为( )
A:-2
B:0
C:2
D:4
A. No, it isn't. B. Thirty-five. C. Yes, we do.
D. It's on the first floor. E. A computer.
方程2x2﹣3=0的一次项系数是( )