Jawabanmu

2014-02-05T17:50:44+07:00
A=2
a+12b-(a+6b)=30
2+12b-2-6b=30
6b= 30
b= 5

sn= n/2 (a +(n-1)5
S50= 25 (2+ (49)5
S50 = 25(2+ 245)
     = 25 x 247