Determine the center & the radius of the circle using the following equation
1., x squared +y squared +8x - 6y = 11 = 0

2., x squared + y squared + 10 y + 9 = 0

3.,( x + 2) squared + (y - 1 ) squared = 196

4.,x squared + (y -8)squared = 100 =

5., (x + 2) squared + y squared = 256 ​