The complex conjugate of 7i is −7i The complex conjugate of a number z is a number with opposite imaginary part.So if z=a+bi then conjugate is: ¯z=a−bi for any a,b∈RWe can note, that if we represent all complex numbers in coordinate system, then for any number: the number z and its conjugate ¯z are symetrical according to "real part" axis.