Jawabanmu

2014-02-26T19:25:09+07:00
1/4 , 2/5 , 3/6 , 4/7 , ...
U25 ?

U1=a=1/4
U2=a+b=2/5

cari b
b = U2 - U1
b = 2/5 - 1/4
b = 3/20

1/4 + 3/20 = 5+3/20 = 8/20 = 2/5
nah, jadi ini termasuk deret aritmetika, karna deret aritmetika, maka memakai rumus
Un = a + (n-1)b
U25 = a + (25-1)b
U25 = a + 24b
U25 = 1/4 + 24(3/20)
U25 = 1/4 + 72/20
U25 = 5+72/20
U25 = 77/20

CMIIW ^_^