a) (7$\frac{4}{9}$ + 4$\frac{7}{11}$) - 3$\frac{4}{9}$
= ($\frac{67}{9}$ - $\frac{31}{9}$) + $\frac{51}{11}$
= 4 + $\frac{51}{11}$
= $\frac{44+51}{11}$ = $\frac{95}{11}$
b) 7$\frac{5}{11}$ - (2$\frac{3}{7}$ + 3$\frac{5}{11}$)
= $\frac{-17}{7}$ + ($\frac{82}{11}$ - $\frac{38}{11}$)
= $\frac{-17}{7}$ + 4
= $\frac{-17+28}{7}$ = $\frac{11}{7}$
c) 7$\frac{5}{9}$ + (2$\frac{3}{4}$ - 3$\frac{5}{9}$)
= $\frac{11}{4}$ + ($\frac{68}{9}$ - $\frac{32}{9}$)
= $\frac{11}{4}$ + 4
= $\frac{11+16}{4}$ = $\frac{27}{4}$
