we are given
[tex] x^2-4x-5 [/tex]
we can use formula
[tex] x^2-(a+b)x+ab=(x-a)(x-b) [/tex]
so, we have
[tex] a+b=4 [/tex]
[tex] ab=-5 [/tex]
now, we can solve for a and b
and we get
[tex] a=5, b=-1 [/tex]
now, we can plug it in formula
[tex] x^2-4x-5=(x-5)(x+1) [/tex]............Answer
