Question

how many pairs of natural numbers are there the difference of whose squares is 36?

Answer 1

Answer:

(x2 - y2) = 45

Or, (x - y)(x + y) = 45

Thus, the factors of 45 possibles are 15, 3, 9, 5, 1 and 45

Hence, numbers are 9 and 6 or 7 and 2 or 23 and 22

So, number of such pairs = 3