Solve by completing the square. Round to the nearest hundredth if necessary.
3x2 – 6x – 24 = 0
(1 point)
Responses
2.65, 3
2.65, 3
–30, 36
–30, 36
4, –2
4, –2
7.58, –1.58
3x2 - 6x - 24 = 0
Divide by 3:
x2 - 2x - 8 = 0
To complete the square, we need to add (2/2)2 = 1 to both sides:
x2 - 2x + 1 = 8 + 1
(x - 1)2 = 9
Take the square root of both sides:
x - 1 = ±√9
x - 1 = ±3
x = 1 ± 3
x = 1 + 3 = 4 or x = 1 - 3 = -2
So the solutions are x = 4 and x = -2. Rounded to the nearest hundredth, this would be x = 4.00 and x = -2.00.
Answer: 4, -2