Let x = your number.
6x = x^2 - 27. Subtract 6x from each side.
0 = x^2 - 6x - 27. Factor
0 = (x-9) (x+3). Set each term equal to zero
(x+3) = 0. Subtract 3 from each side.
x = -3. This is the negative solution.
(x-9) = 0. Add 9 to each side.
x = 9. This is the positive solution.
Nor sure what you're doing on the bottom but use point slope thing
y-0=-2(x+2)
y=-2x+2
So not sure what you're asking but...
yeah, you're right.