如果a+b+c=0则一元二次方程ax+bx+c=0必有一根为要答案和解题思路

Question

如果a+b+c=0则一元二次方程ax+bx+c=0必有一根为
要答案和解题思路

Answer 1

△ = b^2 - 4ac 将 b = -(a+c)代入.= (a+c)^ - 4ac = (a-c)^2 x = (-b ±√△)/ (2a) = [(a+c) ± | a-c|] / (2a) 当a > c,则有：x = [(a+c) ± (a-c)] / (2a) ==> x1 = 1,x2 = c/a 当a < c,则有：x = [(a+c) ± (c-...