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
tim loi giai bai toan: cho hai tap hop A = (1;2;3;4;5;6)va B la tap hop cac so tu nhien le, lon hon 2. goi C la mot tap hop con nao do cua ca hai tap hop A va B. so phan tu nhieu nhat co the cau la
mn giup minh voi
cho day so 3,8,13,18,......
a, neu quy luat cua day so tren
b, viet tap hop a gom 5 so hang lien tiep cua day so tren
c, tinh tong 100 so hang dau tien cua day
d, so 158 la so hang thu bao nhieu cua day
cam mn nhieu love you
1. tim ket qua cua phep nhan.
A = 33...3 * 99...9
--------- ----------
100so3 100so9
2.cho tap hop cac so tu nhien khong vuot qua 100 chia co 7 du 3
a, hay viet tap hop A = 2 cach
b, tinh tong cac phan tu cu A
c, tinh so chu so dung de viet cac tap hop A
3. nguoi ta danh so trang cua mot quyen sach = day so 1;2;3........quyen sach day 300 trang.hoi
a, tinh so chu so dung de danh so trang sach
b, chu so 659 thuoc trang nao va chu so may
cho dãy số 2 5 8 11, ...
a)nêu quy luật của dãy số trên
b) viet tap hop a gom 10 so hang dau tien cua day so
c) xac dinh so thu 20 cua day so , so 101 la so hang thu bao nhieu cua day . Tinh tong cua 20 so hang dau tien cua day
Cho A la tap hop cac so tu nhien lon hon 50va nho hon 100.Viet tap hop A bg cach chi ra cac tinh chat dc trung cho cac phan tu cua no
cho B ={50;51;52...97;98;99 } .dung 1 trong cac ki hieu
thuoc;kg thuoc;bg; tap hop con de bieu dien moi quan he giua 2 tap hop A va B
b] Tap hop A co bao nhieu phan tu? tim tg tat ca cac so la phan tu cua tap hop A
Bai 1 :Tim so tu nhien co 6 chu so biet chu so hang don vi la 4 va neu chuyen chu so do len hang dau tien thi so do tang gap 4 lan.
Bai 2:Cho 3 chu so a,b,c sao cho 0<a<b<c.
a]Viet tap hop cac so tu nhien co 3 chu so gom ca 3 chu so a,b,c.
b]Biet tong 2 so nho nhat trong tap A=488.Tim 3 chu so A,B,C.
cac ban lam bai nay de kiem tra kien thuc cua ban nha, minh da co ket qua va se theo doi ban nao tra loi dung va chi tiet nhat:
Moi tap hop sau co bao nhieu phan tu va neu ten ki hieu dau cham(.) trong cau c va d !
a) Tap hop A cac so tu nhien x ma x - 8= 12
b) Tap hop B cac so tu nhien x ma x + 7 = 7
c) Tap hop C cac so tu nhien x ma x . 0 = 0
d) Tap hop D cac so tu nhien x ma x .0 = 3
3.cho dãy số 7,15,23,31,.....
a,tim so han thu 60 cua day va tinh tong 60 so dautien cua day
b,tim so hang thu 200 cua day va tinh tong cua 200 so dau tien cua day
c,muon viet 200 so dau tien cua day thi phai viet tat ca bn chu so
giúp nha