print('ax^2+bx+c=0')def fangcheng(a,b,c):try:x1=(-b+pow(b**2-4*a*c,0.5))/2*ax2=(-b-pow(b**2-4*a*c,0.5))/2*aprint('x1=%.2f'%x1)print('x2=%.2f'%x2)except:print('次方程无解！')fangcheng(1,-9,20)