Question 90081
find the value for k so that 9m^2-kn^2 will have the factors 3m+7n and 3m-7n
Now factorize 9m^2-kn^2 and equate the factors with given factors as follows
9m^2-kn^2 = (3*m-n*k^0.5)(3*m+n*k^0.5)
equating with given factors we get
k^0.5=7 =>k=49.
Hope this is clear.
Kamal Lohia