x² – 5x – 24

Now, first we have to find out the numbers whose-

Sum = - 5 and

Product = - 24

The numbers are - 8 and 3,

So,

x² – 5x – 24

= x² – 8x + 3x – 24

= x(x – 8) + 3(x – 8)

= (x – 8)(x + 3)