-[5\frac{5}{6}+(-15)-(-3\frac{3}{4})]=-[5\frac{10}{12}+(-15)+3\frac{9}{12}]=-[9\frac{7}{12}+(-15)]=-[-5\frac{5}{12}]=5\frac{5}{12}
zad. 2
-\frac{3}{4}-(-1,2+\frac{5}{8})=-\frac{3}{4}-(-1\frac{1}{5}+\frac{5}{8})=-\frac{3}{4}-(-\frac{6}{5}+\frac{5}{8})=-\frac{3}{4}-(-\frac{48}{40}+\frac{25}{40})=-\frac{3}{4}-(-\frac{23}{40})=-\frac{30}{40}+\frac{23}{40}=-\frac{7}{40}
zad. 3
-[-(-0,9)]+(-\frac{3}{5})-(-0,4)=-0,9-0,6+0,4=-1,5+0,4=-1,1
uwaga
\frac{3}{5}=\frac{6}{10}=0,6