∫ 1 9 x − 1 x d x = ∫ 1 9 x x − 1 x = ∫ 1 9 {\displaystyle \int _{1}^{9}{\frac {x-1}{\sqrt {x}}}dx=\int _{1}^{9}{\frac {x}{\sqrt {x}}}-{\frac {1}{\sqrt {x}}}=\int _{1}^{9}}
