\(\left(1+\dfrac{1}{2}-\dfrac{1}{4}\right)^2\cdot\left(2+\dfrac{3}{7}\right)\)
\(=\left(\dfrac{4}{4}+\dfrac{2}{4}-\dfrac{1}{4}\right)^2\cdot\left(\dfrac{14}{7}+\dfrac{3}{7}\right)\)
\(=\left(\dfrac{5}{4}\right)^2\cdot\dfrac{17}{7}\)
\(=\dfrac{25}{16}\cdot\dfrac{17}{7}=\dfrac{425}{112}\)