Question

Derarimatika 1+3+5+7+.....+un=225nilai n adalah

Answer 1

A = 1
b = 2
Sn = n/2 {2a + (n-1)b}
225 = n/2 {2*1 + (n-1)2}
450 = n * {2 + 2n - 2}
450 = n*2n
450 =
225 =
n =

Answer 2

A = 1
b = 2
un = a + (n-1)b
225 = 1 + (n-1)2
225 = 1 + 2n - 2
225 = 2n -1
2n = 225 + 1
2n = 226
n = 226 /2
n = 113