The number (6n²+ 6n) for natural n is always divisible by
A
6 only
B
12 only
C
6 and 12
D
18
Correct Answer: 6 and 12
6n2 + 6n = 6n(n + 1) n = 1 হলে, 6n(n + 1) = 6.1(1 + 1) = 12 n = 2 ” 6n(n + 1) = 6.2(2 + 1) = 36 n = 3 ” 6n(n + 1) = 6.33 + 1) = 72 ∴ (6n2 + 6n) সর্বদা 6 ও12 দ্বারা বিভাজ্য।