- $\frac{4}{9}$ + $\frac{5}{9}$ . (- $\frac{4}{7}$) + (- $\frac{3}{7}$ ) . $\frac{5}{9}$
= - $\frac{4}{9}$ + $\frac{5}{9}$ . [ (- $\frac{4}{7}$) + (- $\frac{3}{7}$ )]
= - $\frac{4}{9}$ + $\frac{5}{9}$ . $\frac{-7}{7}$
= - $\frac{4}{9}$ + $\frac{5}{9}$ . (-1)
= - $\frac{4}{9}$ - $\frac{5}{9}$
= $\frac{-9}{9}$ = -1