Answer
$(x-1)(x-4)$
Work Step by Step
The following pairs of numbers give a product of $
4
:$
\begin{array}{l}\require{cancel}
\{ 1,4 \}
\text{ }
\{ -1,-4 \}
\text{ }
\{ 2,2 \}
\text{ }
\{ -2,-2 \}
.\end{array}
Of these pairs, the one which gives a sum of $
-5
$ is the pair $\{
-1,-4
\}.$
Hence, the factored form of the given expression, $
x^2-5x+4
$ is
\begin{array}{l}\require{cancel}
(x-1)(x-4)
.\end{array}
