Question

Diket deret aritmatika 4+7+10+13+...+31 jmlh deret aritmatika adalah

Answer 1

4 + 7 + 10 + ... + 31
a = 4
b = 7 - 4 = 3
Un = 31
Un = a + (n - 1)b
31 = 4 + 3(n - 1)
27 = 3n - 3
3n = 30
n = 10

S10 = 5(2(4) + 9(3))
       = 5(8 + 27)
       = 5(35)
       = 175

Answer 2

Cara lain nya gini (4+31)+(7+28)+(10+25)+(13+22)+(16+19) = 5(35)=175