What is the radius of a circle represented by the equation x²+y²x²+y²-2x+4y-18=0

Step-by-step explanation:

i think eq. of circle is

x²+y²-2x+4y-18=0

compare with x²+y²+2gx+2fy+c=0

center is (-g,-f) or (1,-2)

radius is √ (g²+f²-c) = √ ((1) ² + (-2) ² - (-18))

=√ (1+4+18)

=√23