2. 2+4+6+…………+96+98+100 =
3. 1-2+3-4+5-6+7………….+39-40 =
4. 1+3+5…………+37+39-2-4-6-8-………..-38-40 =
Bantu ya kak pake cara 🙂
WARNING!!!!!! JANGAN NGASAL
1. 1+2+3+4+5+……………+48+49+50 =
Jawab:
1. 1275
2. 5100
3. 740
4. -20
Penjelasan dengan langkah-langkah:
1. (1+50) x 50/2 = 51 x 25 = 1275
2. (2+100) x 100/2 = 102 x 50 = 5100
3. (1+39) x 39/2 – 40 = 40 x 19,5 – 40 = 740
4. U20 = 1 + 19 x 2 = 39
S20 = 20/2 (1 + 39)
= 10 x 40
= 400
U21 = 2 + 20 x 2 = 36
S21 = 21/2 (-2 + 42)
S21 = 10,5 x 40
S21 = 420
400 – 420 = -20