Answer:
cccccccccccccccc
Explanation:
c
252 = 7 *36
36 = 6 *6 = 6²
a² -b² = (a + b)(a - b)
7h² - 252k² = 7(h² - 36k²)
= 7(h² - [6k]² )
= 7(h +6k)(h - 6k)
4.4m questions
5.7m answers