7,5+1,2*\frac{5}{12}=7,5+\frac{12}{10}*\frac{5}{12}=7,5+\frac{1}{2}=7,5+0,5=8
2,5:\frac{2}{5}-\frac{1}{4}=2,5:0,4-0,25=6,25-0,25=6
\frac{1}{3}+\frac{1}{6}-(\frac{1}{2})^2=\frac{2}{6}+\frac{1}{6}-\frac{1}{4}=\frac{3}{6}-\frac{1}{4}=\frac{6}{12}-\frac{3}{12}=\frac{3}{12}=\frac{1}{4}
2^3+(\frac{2}{3})^2=8+\frac{4}{9}=8\frac{4}{9}