If a parabola's focus is at (1, −1) and the directrix is at y = 7, what is the equation representing this parabola? x2 − 2x + 16y − 47 = 0
x2 − 47 = 0
x2 − 2x + 16y − 49 = 0
x2 − 2x + 2y2 + 16y − 47 = 0

What is the distance between a and b? round your answer to the nearest tenth. a coordinate plane is shown. point a is located at negative 1, 5, and point b is located at 4, 1. a line segment connects the two points.

Last week , donnell practiced the piano 3 hours longer than marcus . together, marcus and donnell practiced the piano 11 hours . for how many hours did each young man practiced the piano

How many and of which kind of roots does the equation f(x)=x3−x2−x+1