Multiply:

(i) $\frac{7}{11} \times \frac{5}{4}=\frac{7 \times 5}{11 \times 4}=\frac{35}{44}$

(ii) $\frac{5}{7} \times \frac{-3}{4}=\frac{5 \times(-3)}{7 \times 4}=\frac{-15}{28}$

(iii) $\frac{-2}{9} \times \frac{5}{11}=\frac{(-2) \times 5}{9 \times 11}=\frac{-10}{99}$

(iv) $\frac{-3}{17} \times \frac{-5}{-4}=\frac{(-3) \times(-5)}{17 \times(-4)}=\frac{15}{-68}$

(v) $\frac{9}{-7} \times \frac{36}{-11}=\frac{9 \times 36}{(-7) \times(-11)}=\frac{324}{77}$

(vi) $\frac{-11}{13} \times \frac{-21}{7}=\frac{(-11) \times(-21)}{13 \times 7}=\frac{231}{91}=\frac{33}{13}$

(vii) $\frac{-3}{5} \times \frac{-4}{7}=\frac{(-3) \times(-4)}{5 \times 7}=\frac{12}{35}$

(viii) $\frac{-15}{11} \times 7=\frac{-15}{11} \times \frac{7}{1}=\frac{(-15) \times 7}{11 \times 1}=\frac{-105}{11}$