Răspuns:
[tex]10 \frac{1}{2}\times 5 = \frac{10 \times 2 + 1}{2} \times 5 \\ = \frac{20 + 1}{2} \times 5 = \frac{21}{2} \times 5 \\ = \frac{ {}^{1)} 21}{ \: \: 2} \times \frac{ {}^{2)} 5}{ \: \: 1} = \frac{21 \times 10}{2} = \frac{210}{2} = 105 \\ num. \: comun \: e \: 2[/tex]
