tentukan hasil tanpa menghitung satu persatu -100-99-98....-2-1-0+1+2+3+4+.......+48+49+50

-(101×100)/2 + (50×51)/2
-(101×50) + (25×51)
-5050 +1285
-3775

A = -100
B = -99 - (-100) = 1
Jumlah suku :
= 100 + 1 + 50
= 151

S151 :
= n/2 [2a + (n-1) x b]
= 151/2 [2 x (-100) + (151-1) x 1]
= 77,5 [-200 + 150]
= 77,5 x (-50)
= -3775