Răspuns:
[tex] = \frac{5 \times ( - 19.63)}{21} + \frac{5 \times (1.37)}{21} = = \frac{5 \times ( - 19.63) + 5 \times 1.37}{21} = \\ = \frac{5 \times ( - 19.63 + 1.37)}{21} = \\ = \frac{5 \times ( - 18.26)}{21} = \frac{ - 91.3}{21} = - 91.3 \times \frac{1}{21} = \frac{ - 913}{10} \times \frac{1}{21} = \frac{ - 913}{210} [/tex]
