\(\left(1+\dfrac{3}{4}+\dfrac{3}{8}\right)^2-\left(2+\dfrac{7}{8}\right)\)
\(=\left(\dfrac{8}{8}+\dfrac{6}{8}+\dfrac{3}{8}\right)^2-\left(\dfrac{16}{8}+\dfrac{7}{8}\right)\)
\(=\left(\dfrac{17}{8}\right)^2-\dfrac{23}{8}\)
\(=\dfrac{289}{64}-\dfrac{184}{64}\)
\(=\dfrac{105}{64}\)
#\(Toru\)
\(\left(1+\dfrac{3}{4}+\dfrac{3}{8}\right)^2-\left(2+\dfrac{7}{8}\right)\)
\(=\left(\dfrac{8}{8}+\dfrac{6}{8}+\dfrac{3}{8}\right)^2-\left(\dfrac{16}{8}+\dfrac{7}{8}\right)\)
\(=\left(\dfrac{8+6+3}{8}\right)^2-\dfrac{16+7}{8}\)
\(=\left(\dfrac{17}{8}\right)^2-\dfrac{23}{8}\)
\(=\dfrac{289}{64}-\dfrac{23}{8}\)
\(=\dfrac{105}{64}\)