初中数学第九册中,对一元二次方程的解法一般有:直接开平方法、因式分解法、配方法、公式法·但我在指导学生实践与探索规律,创新思维与解题技巧时,发现对一类一元二次方程可根据系数关系便一目了然就知道它的解·定理:对于一元二次方程ax2+bx+c=0(a≠0),若ac-b+1=0,则方程的两 In the ninth book of junior middle school mathematics, the solutions to the one-dimensional quadratic equation generally include: direct open-flat method, factorization method, matching method, and formula method. But when I guide students in practice and exploration of laws, innovative thinking and problem-solving skills, It is found that for a class of unary quadratic equations, its solution and theorem can be known at a glance according to the coefficient relationship: for a quadratic equation ax2+bx+c=0 (a≠0), if ac-b+1=0, then Two of the equations