tìm tích phân 3^x/5^x

\(\int {\frac{{{3^x}}}{{{5^x}}}} \;{\rm{d}}x = \int {{{\left( {\frac{3}{5}} \right)}^x}} \;{\rm{d}}x = \frac{{{{\left( {\frac{3}{5}} \right)}^x}}}{{\ln \frac{3}{5}}} + C = \frac{{{3^x}}}{{(\ln 3 - \ln 5){5^x}}} + C\).