cho m =999...99 .100chu so 9
n=777....77.100chu so 7
tính tong cac chu so m nhan n
cho m=999...99 (100 chu so 9) va n=777....77(100 chu so 7) tinh tong cac chu so cua m nhan n
cho m =999...99 ; n =777.......77 , tinh tong cac chu so m nhan n
tinh tong cac chu so cua a biet a=671nhan 100chu so 9cong chu so 7 cuoi cung cong 2015
cho day so 1,2,3,...,999.tinh tong cac chu so cua day so do
chung to cac phan so sau bang nhau:
7/9 = 77/99 = 777/999
Ta có : \(\frac{77}{99}=\frac{77:11}{99:11}=\frac{7}{9};\frac{777}{999}=\frac{777:111}{999:111}=\frac{7}{9}\)
Mà : \(\frac{7}{9}=\frac{7}{9}=\frac{7}{9}\)
Vậy : \(\frac{7}{9}=\frac{77}{99}=\frac{777}{999}\)
Ta tách : \(\frac{77}{99}=\frac{77:11}{99:11}=\frac{7}{9}\)
\(\frac{777}{999}=\frac{777:111}{999:111}=\frac{7}{9}\)
\(\Rightarrow\frac{77}{99}=\frac{777}{999}\)
tim so chinh phuong n co ba chu so biet rang n chia het cho 5 va neu nhan n voi 2 thi tong cac chu so cua no khong doi
Tim so chinh phuong n co 3 chu so ,biet rang n chia het cho 5 va neu nhan n voi 2 thi tong cac chu so cua no khong doi
Tim so chinh phuong n co ba chu so, biet rang n chia het cho 5 va neu nhan n voi 2 thi tong cac chu so cua no khong thay doi
Tim 1 so co 3 chu so biet khi dem so do nhan nhan voi tong cac chu so trong so do ta duoc 1000
Bang 125 vi 1+2+5=8 ma 8*125=1000