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根据近些年来的中考题与综合练习题都出现|x_2-x_1|的类型,按常规方法,是由一元二次方程 ax~2+bx+c=0(a≠0)的两根 x_1,x_2得:x_1+x_2=-b/a(1) x_1x_2=c/a(2)但在教学中,我发现根与系数的关系可补充下列条
According to the types of |x_2-x_1| in both the mid-exam and the comprehensive exercises in recent years, the conventional method is based on the two x_1 elements of the quadratic equation ax~2+bx+c=0(a≠0). X_2 gets: x_1+x_2=-b/a(1) x_1x_2=c/a(2) But in teaching, I found that the relationship between root and coefficient can be supplemented by the following