Jawabanmu

2014-09-01T10:55:52+07:00
A. 1+3+5+...+99=100+100+...+100(sebanyak25)
=2500
b.1+3+5+...+99-(2+4+6+...+100)
=2500-(102x25)
=2500-2550
=-50
c.-100-99-98-...-1-0+1+2+3+...+50
=-(100+99+98+...+1)+(1+2+3+...+50)
=-(5050)+(1275)
=-3775
3 5 3
2014-09-01T11:37:05+07:00
No. 1
a = 1 ; b = 3-1=2
S99= n/2 [2a + (n-1) b]
= 99/2 [ 2.1 + (99-1) 2]
= 99/2 [2+ 98.2]
= 99/2 [198]
= 9801