The number 7¹² - 2¹² is perfectly divisible by which of the following pairs?
(a) Both 5 and 9
(b) Both 5 and 11
(c) Both 9 and 13
(d) Both 3 and 7

Answer: A. Both 5 and 9

• Answer: (a) Both 5 and 9
• Solution:
1. Use the algebraic identity \(x^n - y^n\). For any positive integer n, \((x^n - y^n)\) is always divisible by (x - y).

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