Question

factorise:
7m^2+67m+36

Answer 1

You know the first terms of the factors must be 7 & 1, since those are the only factors of 7.

So you write: $(7m+x)(m+y)$

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:

$(7m+4)(m+9)$