Suatu deret aritmatika 5+3+1+(-1)+(-3),..... Tentukan jumlah 10 bilangan pertama

Dik = a = 5
b = U2-U1 = 3-5 = -2
Dit = S10

S10 = (1/2 n (2 a + (n-1) b)
S10 = (10/2 (10 + 9 × -2))
S10 = (5 (10 + (-18))
S10 = (5 × -8)
S10 = -40