Plz and explain how to find the surface area

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)

[10 points, algebra 2-simplifying complex fractions]according to my answer key the restrictions are -1 and 4. but why not positive 1?

What sums are equal to 6/12? choose all answers that are correct a.6/12+6/12+6/12+6/12+6/12+6/12 b.2/12+1/12+1/12+2/12 c.5/12+1/12 d.1/12+1/12+1/12+3/12 plz : )