If Un = n(n2 + 1), evaluate U5 - U4
A
18
B
56
C
62
D
80
Verified Correct Answer: C.
Step-by-Step Mathematical Solution
Un = n(n2 + 1)
U5 = 5(2 + 1)
= 5(25 + 1)
= 5(26) = 130
U4 = 4(42 + 1) = 4(16 + 1)
= 4(17) = 68
U5 - U4 = 130 - 68
= 62
Source: Myschool Past Questions Archive (Record #36850)