
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.



=(1+98-99-100)+(2-3-4+5)+(6-7-8+9)+...+(95-96-97+98)
=-100+0+0+0+0+0..................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

A) SỐ 2020 CÓ THUỘC DÃY SỐ TRÊN
Số hạng thứ 100 của dãy số đó là :
2 + (100 - 1) x 4 = 398
Tổng 100 số hạng đầu tiên của dãy số đó là :
(2 + 398) x 100 : 2 = 20000
>>>>>> Lưu ý : Ta áp dụng các công thức với dãy số cách đều :
+) Tổng = (số đầu + số cuối) x số số hạng : 2.
+) Số hạng thứ n = số hạng thứ nhất + (n - 1) x khoảng cách giữa hai số liền nhau.

a) 1+(-2)+3+(-4)+..+19+(-20) {có 20-1+1=20(số hạng)}
= [1+(-2)]+[3+(-4)]+..+[19+(-20)] {có 20:2 = 10(tổng)}
=(-1)+(-1)+...+(-1) {có 10 số hạng}
=(-1).10
= -10

22 + 24 + 26 + 28
Vì 2 : 1 = 2; 4 : 2 = 2; 6 : 3 = 2; 8 : 4 = 2
Vậy số mũ của số hạng 100 là: 50
số số hạng là:
(100-2):2+1=98:2+1=50
vậy số số hạng là 50
Số số hạng là
(100 - 2) : 2 + 1 = 50 ( SSH )
Kick mk nha
# USAS - 12 #