Pomocy!!! Kompletnie tego nie ogarniam!!! Ktos pomoże?
1.(5-1/jedna druga) :(2/3 ósme - 1,75) 
PROSZE O PEŁNĄ

$(5-\frac{1}{\frac{1}{2}}):(\frac{\frac{2}{3}}{8}-1,75)=(5-1*\frac{2}{1}):(\frac{2}{3}*\frac{1}{8}-\frac{175}{100})=(5-2):(\frac{1}{12}-\frac{175}{100})=3:(\frac{100}{1200}-\frac{2100}{1200})=3:(-\frac{2000}{1200})=3:(-\frac{20}{12})=3:(-\frac{5}{3})=3*(-\frac{3}{5})=-\frac{9}{5}=-1\frac{4}{5}$