Đáp án:
$\begin{array}{l}
A = \dfrac{{{x^2}y - 7xy}}{{5xy}}\\
= \dfrac{{xy.\left( {x - 7} \right)}}{{5xy}}\\
= \dfrac{{x - 7}}{5}\\
= \dfrac{{107 - 7}}{5}\\
= \dfrac{{100}}{5}\\
= 20\\
B = \dfrac{{{x^2} - 6x + 9}}{{2x - 6}}\\
= \dfrac{{{{\left( {x - 3} \right)}^2}}}{{2\left( {x - 3} \right)}}\\
= \dfrac{{x - 3}}{2}\\
= \dfrac{{17 - 3}}{2}\\
= \dfrac{{14}}{2} = 7
\end{array}$
