同学们在解竞赛题时,常会遇到条件或隐含条件a+b+c=0,许多同学不知它有何用?下面就举例说明它的功能.结论1若a+b+=0(a≠0),则一元二次方程dx~2+bx+c=0必有一个根为1;反之也成立.(请同学自己完成证明) When students solve a competition problem, they often encounter conditions or implied conditions a+b+c=0, many students do not know what it’s use? Here’s an example to illustrate its function. Conclusion 1 if a + b + = 0 (a ≠ 0), the quadratic equation dx~2+bx+c=0 must have a root of 1, and vice versa (please ask the classmate to complete the proof)