Question

[Lê Ngọc Huyền]

Bài 9: Tìm A biết:

A=7/10+7/10^2+7/10^3

Answer 1

[Cold Wind]

\(A=\frac{7}{10}+\left(\frac{7}{10}\right)^2+\left(\frac{7}{10}\right)^3\)

     \(=\frac{7}{10}+\frac{49}{100}+\frac{343}{1000}\)

       \(=\frac{700+490+343}{1000}\)

        \(=\frac{1533}{1000}\)

          \(=1,533\)