помогите решить 6 примеров -3/4•5/7=? -1/3•(-9/13)=? 3/4•(-16)=? -6:5/6=? -7/8:7=? -3 4/9:(-1 13/18)=?

[tex] - \frac{3}{4} \times \frac{5}{7} = - \frac{15}{28} [/tex]

[tex] - \frac{1}{3} \times ( - \frac{9}{13} ) = \frac{9}{39} = \frac{3}{1 3} [/tex]

[tex] \frac{3}{4} \times ( - 16) = 3 \times ( - 4) = - 12[/tex]

[tex] - 6 \div \frac{5}{6} = - 6 \times \frac{6}{5} = - \frac{36}{5} = - 7.2[/tex]

[tex] - \frac{7}{8} \div 7 = - \frac{7}{8} \times \frac{1}{7} = - \frac{1}{8} = - 0.125[/tex]

[tex] - 3 \frac{4}{9} \div ( - 1 \frac{13}{18} ) = - \frac{31}{9} \div ( - \frac{31}{18} ) = [/tex]
[tex] = - \frac{31}{9} \times( - \frac{18}{31} ) = 2[/tex]