Khong thuc hien phep tinh de tim ket qua.Hay chung minh rang cac tong sau lon hon 1

M = \(\frac{3}{7}+\frac{3}{8}+\frac{3}{10}\)

Khong thuc hien phep tinh de tim ket qua. Hay chung minh rang cac tong sau lon hon 1

N = \(\frac{21}{90}+\frac{31}{72}+\frac{21}{40}+\frac{-1}{45}+\frac{-1}{50}\)

Khong thuc hien phep tinh de tim ket qua. Hay chung minh rang tong sau lon hon 1

N = \(\frac{21}{90}+\frac{31}{72}+\frac{21}{40}+\frac{-1}{45}+\frac{-1}{50}\)

Voi 4 chu so 2 va cach phep tinh, hay thuc hien cac phep tinh de duoc ket qua la 9

khong thuc hien phep tinh,hay tim y trong tung phep tinh sau day(nho giai thich do nha)

1)trong mot phepnhan co thua so thu hai la 64, khi thuc hien phep nhan, ban Minh da viet cac tich rieng thang cot voi nbhau nen ket qua tim duoc la 870. tim tich dung cua phep nhan

2 ) Khi thuc hien phep nhan 983 voi 1 so co 3 chu so , ban binh da dat tich rieng thu 2 thang cot voi tich rieng thu 3 nen duoc ket qua la 70776 . Em hay tim thua so co 3 chu so chua biet trong phep nhan tren , biet chu so hang tram hon chu so hang chuc 1 don vi

BAI1: CHO BIEU THUC.

A= 1494 x 1495 x 1496

KHONG THUC HIEN PHEP TINH GIAI THICH VI SAO

a; a chia het 180

b; a chia het 495

BAI2:CHUNG MINH RANG : n thuoc N thi cac so sau chia het cho 9

a; 10^n-1

b; 10ⁿ⁺⁸

BAI3: TIM DIEU KIEN n thuoc N de so 10^n-1 chia het cho 9 va 11

khi thuc hien phep cong cac so thap phan mot ban da viet nham dau phay cua mot so hang sang ben phai 1 hang do do duoc ket qua la 692,22.Ban hay tim 2 so do biet rang tong dung bang 100,56

khong thuc hien phep tinh , cho biet cac tong hoac hieu sau day la nguyen to hay hop so

3²+3.17+3.43^3;   7+7²+7³+7⁴+7^{5 ;} 46-30+2002 ; 3.4.5.6.7+7.8.9.10