-100-99-98-...-2-1-0+12+...+48+49+50

-50 sampai 50 dianggap nol
maka, jumlahkan = -100 - 99 - ..... - 51 → ada 50 bilangan
                            = (50/2) x (-100 - 51)
                            = 25 x (-151)
                            = -3.775