\(5+2.15+12.4=5+30+48=83\)

\(\Rightarrow B\)

\(5,67:0,8+5,67\times2,5-5,67+5,67\times7,25\)

\(=5,67\times1,25+5,67\times2,5-5,67\times1+5,67\times7,25\)

\(=5,67\times\left(1,25+2,5-1+7,25\right)\)

\(=5,67\times10\)

\(=56,7\)

\(d,\dfrac{3}{7}+\left(-\dfrac{5}{2}\right)+\left(-\dfrac{3}{5}\right)=\dfrac{30+\left(-175\right)+\left(-42\right)}{70}=-\dfrac{187}{70}\)