The general form of the equation of a circle is 7x2 + 7y2 − 28x + 42y − 35 = 0. the equation of this circle in standard form is the center of the circle is at the , and its radius units.

7x2 + 7y2 − 28x + 42y − 35 = 0
7/7x2 + 7/7y2 − 28/7x + 42/7y − 35/7 = 0

x² + y² - 4 x + 6 y - 5 = 0
( x² - 4 x + 4 ) + ( y² + 6 y + 9 ) - 4  - 9 - 5 = 0
The equation in the standard form is:( x - 2 )² + ( y + 3 )² = 18
                                                           ( x - 2 )² + ( y - (-3) )² = 18

The center is at the point ( 2, - 3 ).Its radius is: √18 = 3√2 units

 the answer is 
a) (x-2)²+(y+3)²=18
b) The center of the circle is at the point (2,-3)
c) the radius is 3√2 units