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[tex]2 \times ( \frac{5}{7} - \frac{1}{3} ) - ( \frac{2}{7} ) {}^{2} \times \frac{14}{3} \\ \\ 2 \times ( \frac{15}{21} - \frac{7}{21} ) - \frac{4}{49} \times \frac{14}{3} \\ \\ 2 \times ( \frac{8}{21} ) - \frac{56}{147} \\ \\ \frac{16}{21} - \frac{56}{147} \\ \\ \frac{16}{21} - \frac{8}{21} \\ \\ \frac{8}{21} [/tex]
