Question 83584
Find a value for k so that 9m squared-kn squared will have the factors 3m+7n and 3m-7n 
-------------------
9m^2-kn = (3m+7n)(3m-7n)
9m^2-kn = 9m^2-49n^2
-kn = -49n^2
k= (-49n^2)/(-n)
k = 49n
=============
Cheers,
Stan H.