Answer:
y= -3.5x+57.5.
Step-by-step explanation:
Answer:
I think B and C
Step-by-step explanation:
Because they are the only ones that have more than two so you know it would be them
ANSWER
![y = 3 \pm \sqrt{21}](https://tex.z-dn.net/?f=y%20%20%20%3D%203%20%5Cpm%20%5Csqrt%7B21%7D%20)
EXPLANATION
The quadratic equation is:
![{y}^{2} - 6y - 12 = 0](https://tex.z-dn.net/?f=%20%7By%7D%5E%7B2%7D%20%20-%206y%20-%2012%20%3D%200)
Group variable terms:
![{y}^{2} - 6y = 12](https://tex.z-dn.net/?f=%20%7By%7D%5E%7B2%7D%20%20-%206y%20%3D%2012)
Add the square of half, the coefficient of y to both sides.
![{y}^{2} - 6y + ( - 3) ^{2} = 12 + ( - 3) ^{2}](https://tex.z-dn.net/?f=%20%7By%7D%5E%7B2%7D%20%20-%206y%20%20%2B%20%28%20-%203%29%20%5E%7B2%7D%20%3D%2012%20%2B%20%28%20-%203%29%20%5E%7B2%7D%20)
![{y}^{2} - 6y + 9= 12 + 9](https://tex.z-dn.net/?f=%20%7By%7D%5E%7B2%7D%20%20-%206y%20%20%2B%209%3D%2012%20%2B%209)
The LHS us now a perfect square trinomial:
![{(y - 3)}^{2}= 21](https://tex.z-dn.net/?f=%7B%28y%20-%203%29%7D%5E%7B2%7D%3D%2021)
Take square root:
![y - 3 = \pm \sqrt{21}](https://tex.z-dn.net/?f=y%20-%203%20%3D%20%20%5Cpm%20%5Csqrt%7B21%7D%20)
![y = 3 \pm \sqrt{21}](https://tex.z-dn.net/?f=y%20%3D%203%20%5Cpm%20%5Csqrt%7B21%7D%20)
The first choice is correct.
Three
Reason:
Two to hold the ladder and one to screw the bulb