Let \( a \) be a positive real number such that \( \displaystyle\int\limits_{0}^{a} e^{\,x-[x]}\,dx = 10e - 9 \) Where \( [x] \) is the greatest integer less than or equal to \( x \). Then \( a \) is equal to:
\( 10 + \log_{e} 2 \)
\( 10 - \log_{e}(1+e) \)
\( 10 + \log_{e} 3 \)
\( 10 + \log_{e}(1+e) \)