Write f(x)=x^2+8x+15 in standard form

Which quadratic function best fits this data? x y 1 32 2 78 3 178 4 326 5 390 6 337 a. y=11.41x2+154.42x−143.9 b. y=−11.41x2+154.42x−143.9 c. y=11.41x2+154.42x+143.9 d. y=−11.41x2+154.42x+143.9

True or false? a circle could be circumscribed about the quadrilateral below.

How many sides does a regular polygon have if each exterior angle measure is 45 degrees explain your answer, i really don't understand this.