[tex] - \frac{7}{10} \times \frac{5}{14} + \frac{4}{21} \times \frac{7}{10} - \frac{7}{10} \times \frac{6}{35} = \\ - \frac{7}{14} \times \frac{5}{10} + \frac{4}{10} \times \frac{7}{21} - \frac{7}{35} \times \frac{6}{10} = \\ - \frac{1}{4} + \frac{2}{5} \times \frac{1}{3} - \frac{1}{5} \times \frac{3}{5} = \\ - \frac{1}{4} + \frac{2}{15} - \frac{3}{25} = \\ \\ \frac{ - 75 + 40 - 36}{300} = \\ \\ - \frac{75 - 40 + 36}{300} = \\ \\ - \frac{71}{300} [/tex]
sper că te-am ajutat ;)
