[tex]( \frac{3}{4} \times \frac{4}{3} - \frac{1}{2} ) - \frac{4}{9} [/tex]
[tex] = (1 - \frac{1}{2}) - \frac{4}{9} [/tex]
[tex] = \frac{1}{2} - \frac{4}{9} [/tex]
[tex] = \frac{9-8}{18} [/tex]
(se aduce la același numitor)
= 1/18