Question

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

Answer 1

Perhatikan , terdapat deret aritmatika :
13,23,33,43,........
beda = 10
suku awal = 13
Maka :
Un = a + (n - 1)b
1003 = 13 + (n - 1)10
1003 = 13 + 10n - 10
1003 = 10n - 3
1000 : 10 = n
100  =  n

Maka
y = [ 100/2 (13 + 1003) ]  +  100x
y = 50 (1016)  +  100x
y = 50800 + 100x