Your second equation has 2 x-intercepts because its curve goes beneath the x-axis, meaning it crosses the x-axis twice. Your first equation has only one x intercept because its vertex touches the x-axis. The transformation that occurred was a vertical shift downwards, (since the image function has that little -7 at the end : ) )
When dividing by a negative the sign changes to the opposite.
The answer is -8 I know this as well as