To complete the square, assuming the coefficient of the squared term is 1 (as it is here), we simply need to divide the coefficent of the second term by 2 and square the result.
In this case, (25/2)2 or 625/4
The perfect square polynomial would then be written as:
- z2 + 25z + 625/4 or
- (z + 25/2)2 in factored form