Explicação passo-a-passo:
[tex]a) \: \frac{1}{2} \: \frac{1}{4} \: \frac{2}{3} = \frac{6 \times 1}{12} \: \frac{3 \times 1}{12} \: \frac{4 \times 2}{12} = \frac{6}{12} \: \frac{3}{12} \: \frac{8}{12} \\ \\ b) \: \frac{3}{4} \: \frac{23}{5} = \frac{5 \times 3}{20} \: \frac{4 \times 23}{20} = \frac{15}{20} \: \: \frac{92}{20} \\ \\ c) \: \frac{4}{6} \: \frac{2}{3} \: \frac{1}{4} = \frac{2 \times 4}{12} \: \frac{4 \times 2}{12} \: \frac{3 \times 1}{12} = \frac{8}{12} \: \frac{8}{12} \: \frac{3}{12} [/tex]
