You have the following trinomial given in the exercise:
[tex]p^2-8p+7[/tex]
Notice that is is a trinomial because it is a polynomial that has three terms.
In order to factor it (as the product ot two binomials) you can find two numbers whose sum is -8 and whose sum is 7. These numbers would be -1 and -7, because:
[tex]\begin{gathered} -1-7=-8 \\ \\ \\ (-1)(-7)=7 \end{gathered}[/tex]
Then, you can factor it
[tex](p-1)(p-7)[/tex]
The answer is:
[tex](p-1)(p-7)[/tex]
