7) a) [tex] \frac{3}{4}:(-1 \frac{1}{2} )*(-17+ 3^{2})+(-15+18)= [/tex]

b) [tex] (-19+2^4)*[ \frac{1}{15}- \frac{8}{45}*(-0,9+1 \frac{2}{5})]= [/tex]

c) [tex] -2 \frac{7}{9} * [- \frac{1}{3} + \frac{1}{7} *( \frac{2}{5} - \frac{1}{6} )]=[/tex]

d) [tex]1 \frac{2}{15} :[-1 \frac{1}{6} +1 \frac{4}{25} :(3 \frac{4}{15} - 1\frac{2}{6}) =[/tex]