Page 19 - DIGITAL BOOK MUHAMMAD AZWARDI NASUTION
P. 19
a) 2
S = n 5 ( n + ) 8
n
S = 10 . 5 ( 10+ ) 8 S = 9 . 5 ( 9 + ) 8
10
9
= 10 ( 58 ) = 9(53)
= 580 = 477
U = S − S n− 1
n
n
U = S − S 9
10
10
= 580 - 477
= 103
