Given,

3 + 23z – 8z²

Now first find the numbers whose-

Sum = 23 and

Product = - 8 × 3 = 24

Required numbers are 24 and 1,

So we get;

3 + 23z – 8z²

= 3 + 24z – z – 8z²

= 3(1 + 8z) – z(1 + 8z)

= (1 + 8z)(3 – z)