两边同除以 2 得 x^2-50x-200=0 ,a = 1 ,b = -50 ,c = -200 ,判别式 = b^2-4ac = (-50)^2-4*1*(-200) = 3300 ,所以 x1 = (50-√3300)/2 = 25-5√33 ,x2 = (50+√3300)/2 = 25+5√33 .