You know the first terms of the factors must be 7 & 1, since those are the only factors of 7.
So you write: [tex](7m+x)(m+y) [/tex]
Both the second and third term are positive, so x & y are both positive.
From there, all you can really do is plug in all factors of 36 as x or y until you find that the second term adds up to 67.
And you find the only one that works is:
[tex](7m+4)(m+9)[/tex]
