In this question , we have to rewrite the given expression by grouping and the expression is
[tex] 5m +5n [/tex]
First we have to check what is common here. And as we see that 5 is there with both terms. So the common factor is 5 here.
And on taking out 5 , we will get
[tex] 5m +5n = 5(m+n) [/tex]
And that's the required factored form.