【实训4-3】 求解一元二次方程的实根 分别输入a、b、c三个数，求解一元二次方程ax2+bx+c=0的实根，假设a≠0。设计要求：在三个文本框中分别输入a、b、c的值，单击“解方程”按钮，则在Label4和Label5中分别显示两个根。

―Wht cn I do for you ―__________.I’m looking for tie for my fther B．Yes, you cn give tie to me C．No, I cn do it myself D．I cn do wht I wntA．I’m looking for a tie for my fatherB．Yes, you can give a tie to meC．No, I can do it myselfD．I can do what I want