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

correct answer:

i^31 = -i

x = -4

step-by-step explanation:

- 20 - 4(x + 3) = 4x

=> -20 - 4x - 12 = 4x

=> - 32 -4x = 4x

=> -32 = 4x + 4x

=> - 32 = 8x

=> -32/8 = x

=> -4 = x