Which of the following equations have only one solution? Select all correct answers. x²-x-6=0
5 x2 + 20 x+ 20 = 0
9x2 - 25 = 0
4x2+4 x=0
12+ 6 x+9= 0​

The equations which have only one solution is: 5x²+20x+20=0,

Step-by-step explanation:

5x^2 + 20x + 20 = 0

12+ 6x +9= 0​

Step-by-step explanation:

5x^2 + 20x + 20 = 0  /5             12 + 6x + 9 = 0        

x^2 + 4x + 4 = 0                          6x = -9-12

(x+2)^2=0                                    6x = -21

x + 2 = 0                                      x = -21/6

x=-2                                             x = -3.5

answer: i'm not sure

step-by-step explanation: