Ma ajutați, va rog, nush cum sa fac

[tex] \frac{4}{9} \times \frac{5}{18} + \frac{4}{9} \times ( - \frac{1}{6} )[/tex]
[tex] \frac{2}{9} \times \frac{5}{9} - \frac{2}{9} \times \frac{1}{3} [/tex]
[tex] \frac{10}{81} - \frac{2}{27} [/tex]
[tex] \frac{4}{81} [/tex]