i completed a challenge that was supposed to give me 400 or 300 points but I don't have it. where is it?

Question 6 (10 points) ✓ saved what is the center of a circle described by the equation x2 + y2 +10y = -16? . (0,-5) (0,5) (-5,0) (5,0)

What value of x is in the solution set of –5x – 15 > 10 + 20x?

What will the graph look like for a system of equations that has no solution? a. the lines will be perpendicular. b. the lines will cross at one point. c. both equations will form the same line. d. the lines will be parallel.