a3 - 9 + (a+1)3 রাশিটির উৎপাদক (a - 1) এবং অপর একটি উৎপাদক? )
A
2a2 + 5a + 8
B
2a2 - 5a + 8
C
2a2 - 6a + 8
D
2a2 + 5a - 8
Correct Answer: 2a2 + 5a + 8
a3 - 9 + (a + 1)3 = a3 - 9 + a3 + 3a2 + 3a + 1 = 2a2 + 3a2 + 3a - 8 = 2a3 - 2a2 + 5a2 - 5a + 8a - 8 = 2a2(a - 1) + 5a(a - 1) + 8(a - 1) = (a - 1)(2a2 + 5a + 8)