两边同乘x x^3 + 5x^2 + 25X = 0.
x^3 + 5(x^2 + 5x) = 0.
两边同加125.
125 = x^3 + 5(x^2 + 5x + 25) = x^3
• 解三 -wxcfan123- ♂ (105 bytes) () 10/16/2022 postreply 11:54:43
• 解四 -wxcfan123- ♂ (117 bytes) () 10/16/2022 postreply 19:35:50
• X^3 = 125 -> X=5 -> x^2 + 5x + 25 == 25 + 25 + 25 = 0. -2022_2092- ♂ (0 bytes) () 02/02/2023 postreply 11:10:17