Written as the product of its prime factors, 756= 3^3 x 2^2 x 7. Find the smallest positive integer k such that 756k is a perfect square.
756= 3^3 x 2^2 x 7
k = 3 * 7 = 21
756 (3 *7) = 3^4 x 2^2 x 7^2 = 3^2 x 3^2 x 2^2 x 7^2 = ( 3 * 3 * 2 * 7)^2 =
(9 * 2 * 7)^2 = (126)^2
