Let z=x+iy
(2z+iz−1)=2(x+iy)+i(x−1)+iy=2x+(2y+1)i(x−1)+iy×2x−(2y+1)i2x−(2y+1)i
Re(2z+iz+1)=(2x2)+(2y+1)22x(x−1)+y(2x+1)=1
⇒2x2+2y2−2x+y=4x2+4y2+4y+1
⇒2x2+2y2+2x+3y+1=0
⇒x2+y2+x+23y+21=0
Circle with center (−21,−43)
r=41+169−21=164+9−8=45⇒d=25
where, d=diameter of the given circle.