两个及多个一元二次方程有公共实根问题的解题思路与方法有三；一是设出公共实根a．由公共实报的定义，则a必适合每一个方程．再设法消去。的二次项，然后对所得结果进行讨论（保证各方程均有实根），即可求出公共实根。的值；二是分别设出两方程的实根，利用根与系数的关系列 There are three ideas and methods for solving common root problems of two or more unary quadratic equations; one is to set up public roots a. From the definition of public report, a must be suitable for each equation. Try to eliminate it again. The second term, then discuss the results (to ensure that each equation has a real root), you can find the public root. The second is to set the real roots of the two equations, using the relationship between the root and the coefficient