Question

Tentukan nilai y = x+13+x+23+x+33+...+x+1003

Answer 1

A = x+13
b = 10
Un = a+(n-1)b
x+1003 = x+13+(n-1)10
990 = 10n-10
10n = 1000
n = 100
Artinya ada 100 barisan
Sn = n/2 (a+Un)
S100 = 100/2 (x+13+x+1003)
S100 = 50(2x+1016)
S100 = 100x+50800