Answer:
(8,-3)
Step-by-step explanation:
The given parabola is

We factor -3 from the first two terms to get:

Add and subtract the square of half the coefficient of x


We simplify to get:

We compare this to y=a(x-h)²+k,
The vertex is (h,k)=(8,-3)
Answer:
Step-by-step explanation:
Properties of a circumcenter;
1). Circumcenter of a triangle is a point which is equidistant from all vertices.
2). Point where perpendicular bisectors of the sides of a triangle meet is called circumcenter of the triangle.
From the picture attached,
9). AG = GB = GC = 21
10). BC = 2(DC)
= 2×16
= 32
11). By applying Pythagoras Theorem in ΔGFB,
GB² = GF² + FB²
(21)² = GF² + (19)²
441 = GF² + 361
GF² = 441 - 361
GF = 
GF = 8.9
12). By applying Pythagoras theorem in ΔGDB,
GB² = DG² + BD²
(21)² = (DG)² + (16)² [BD = DC = 16]
DG² = 441 - 256
DG = √185
DG = 13.6
1: 5 2: 9 or 10
For question 1 we can round 115 to 100, 5x100 is 500 which is closer to 545 than 7x100 = 700.