Tìm x, biết x . (3/5)^8 = ( 3/5)^10

12/15

Tìm x, biết \(x \cdot {\left( {\frac{3}{5}} \right)^8} = {\left( {\frac{3}{5}} \right)^{10}}\)

\(x = \frac{{25}}{9}\);

\(x = \frac{3}{5}\);

\(x = \frac{9}{{25}}\);

\(x = \frac{9}{5}\).

Giải thích

Đáp án đúng là: C

\(x \cdot {\left( {\frac{3}{5}} \right)^8} = {\left( {\frac{3}{5}} \right)^{10}}\)

\(x = {\left( {\frac{3}{5}} \right)^{10}}:{\left( {\frac{3}{5}} \right)^8}\)

\(x = {\left( {\frac{3}{5}} \right)^{10 - 8}}\)

\(x = {\left( {\frac{3}{5}} \right)^2}\)

\(x = \frac{9}{{25}}\)

Vậy \(x = \frac{9}{{25}}\)