y=3x^{2}+12x+11

\to x=\frac{-b}{2a} = \frac{-12}{2 \cdot 3}=-2

y=-x^{2}-6x-8

\to x=...

y=-2x^{2}+12x-19

\to x=...

y=2x^{2}+12x+17

\to x=...

y=-3x^{2}+18x-28

\to x=...

y=-3x^{2}+12x-12

\to x=...

y=-x^{2}-2x

\to x=...

y=-3x^{2}-6x-2

\to x=...

y=-2x^{2}+12x-20

\to x=...

y=-x^{2}+6x-8

\to x=...

y=3x^{2}-18x+28

\to x=...

y=x^{2}-6x+11

\to x=...

y=-3x^{2}-6x-2

\to x=...

y=-x^{2}-4x-3

\to x=...

y=2x^{2}+4x+4

\to x=...

y=3x^{2}-6x+5

\to x=...

y=2x^{2}+12x+17

\to x=...

y=-x^{2}+6x-11

\to x=...

y=-3x^{2}+12x-14

\to x=...

y=-3x^{2}-18x-26

\to x=...

y=-2x^{2}

\to x=...

y=-3x^{2}-12x-14

\to x=...

y=2x^{2}+12x+19

\to x=...

y=3x^{2}+1

\to x=...