Các câu hỏi tương tự
cho dãy số:
A1 = 1+2
A2 = 3+4+5
A3 = 6+7+8+9
A4 = 10+11+12+13+14
a, tìm A100
b,tính tổng S =A1 + A2 + ... + A100
bai 1tinh : 1 + 2 + 3 + ... + 1998 + 1999bai 2 : tinh tong cua a) tat ca cac chu so tu nhien co 3 chu sob) tat ca cac so le ci 3 chu sobai 3 : tinh tong a) tat ca cac so : 2 , 5, 8,11, ... , 296b) tat ca cac so : 7 , 11 ,15 , 19 , ..... , 283bai 12cho day soa) 1 , 4 , 7 , 10 , 13 ,19b) 5 , 8 , 11 , 14 , 17 , 20 , 23 , 26 , 29c) 1 , 5 , 9 , 13 , 17 , 21 , ......hay tim cong thuc bieu dien cac day so trenmong cac ban lam ho minh minhdang can gap ban nao tra loi dau tien minh se tich ngay lap tuc
Đọc tiếp
bai 1
tinh : 1 + 2 + 3 + ... + 1998 + 1999
bai 2 : tinh tong cua
a) tat ca cac chu so tu nhien co 3 chu so
b) tat ca cac so le ci 3 chu so
bai 3 : tinh tong
a) tat ca cac so : 2 , 5, 8,11, ... , 296
b) tat ca cac so : 7 , 11 ,15 , 19 , ..... , 283
bai 12
cho day so
a) 1 , 4 , 7 , 10 , 13 ,19
b) 5 , 8 , 11 , 14 , 17 , 20 , 23 , 26 , 29
c) 1 , 5 , 9 , 13 , 17 , 21 , ......
hay tim cong thuc bieu dien cac day so tren
mong cac ban lam ho minh minhdang can gap ban nao tra loi dau tien minh se tich ngay lap tuc
cho day so:2;7;12;17;22..................
a) tim ra quy luat cua day so.
b)viet tap hop B co 5 phan tu bat dau tu so hang thu 5.
c)tinh tong 100 so tu nhien cua day so.
ai lam bai nhanh va dung nhat se duoc tick.(nho viet ca loi giai)
bai 1
cho tong : S = 5 + 8 + 11 +14 = ....
a) tim so hang thu 100 cua tong
b) tinh tong 100 so hang dau tien
bai 2
cho tong : S = 7 + 12 + 17 + 22 + .......
a) tim so hang thu 50 cua tong
b) tinh tong 50 so hang dau tien
bai 3
tinh tong cua tat ca cac so hang tu nhien x , biet x la so tu nhien co 2 chu so va 12 < x <91
ban nao lam ho minh 3 bai tren voi ma ban nao nao lam ra dau tien minh se tich ngay va lun
bai 1 tinh nhanh 2.53.12+4.6.87-3.8.40
5.7.77-7.60+49.25-15.42
bai 3 tinh gia tri bieu thuc 1 cach hop ly
b,B=1+2-3-4+5+-7-8+9+10-11-12+......-299-300+301+302
bai 4 tong cua 2 so tu nhien gap 3 lan hieu cua chung tim thuong cua ba so ay
BAN NAO GIAI DUOC TAT CA CHO 3 TICK 1BAI CHO 1 TICK 2 BAI CHO 2 TICK
tim quy luat cua day so nay va tinh tong :
1+9+18+...+990+999
tim x biet
1/3x+2/5(x-1)=4
1/2-1/3:3x0-=5
tim stn nho nhat chia cho 5, cho 7, cho 9 co so du theo thu tu la 3;4;5
Tinh tong: 1-5/6+7/12-9/20+11/30-13/42+15/56-17/12+19/90
2 + 3 = 10 8 + 4 = 96
7 + 2 = 63 6 + 5 = 66
Tim quy luat va cho biet ket qua o phep tinh 9 + 5 =?
Vua chieu mk thi hsg thi ra 126 ( Tong 2 so nhan voi so dau tien )
khong gia tri xet xem cac tong sau day co chia het cho 9 hay khong 2*3*4*5*6*7+8*9*10*11*12