[RESOLVED] Factorise

(a) Factorise x^2 - 16


(b) Use your answer to part (a) to find the other two factors of 39984


(a) x^2 - 16 = (x-4)(x+4)


I have done part (a) but I do not know how to use the answer in part (a) to solve for (b). Please help. Thanks a lot. :)

Presumably:
x² - 16 = 39984
x² = 40000
x = 200

Using (a):
39984 = 196 * 204

Thanks Logophobic! :)