Explications étape par étape:
[tex]a = \frac{ - 45}{36} \div \frac{5}{ - 9} = \frac{ - 45}{36} \times \frac{ - 9}{5} = \frac{ - 9 \times 5 \times - 9}{9 \times 4 \times 5} = \frac{9}{4} [/tex]
[tex]b = - \frac{7}{5} \div \frac{9}{50} = - \frac{7}{5} \times \frac{50}{9} = \frac{ - 7 \times 5 \times 10}{5 \times 9} = \frac{ - 70}{9} [/tex]
[tex]c = \frac{16}{7} \div \frac{ - 12}{21} = \frac{16}{7} \times \frac{ - 21}{ 12} = \frac{4 \times 4 \times - 3 \times 7}{7 \times 4 \times 3} = - 4[/tex]
[tex]d = \frac{ - 3}{ - 4} \div \frac{ - 5}{ - 28} = \frac{ - 3}{ - 4} \times \frac{ - 28}{ - 5} = \frac{ - 3 \times 7 \times - 4 }{ - 4 \times - 5} = \frac{ - 21}{ - 5} [/tex]
[tex]e = \frac{ - 11}{8} \div \frac{33}{12} = \frac{ - 11}{8} \times \frac{12}{33} = \frac{ - 11 \times 4 \times 3}{4 \times 2 \times 11 \times 3} = \frac{ - 1}{2} [/tex]
[tex]f = \frac{7}{2} \div \frac{ - 3}{4} = \frac{7}{2} \times \frac{4}{ - 3} = \frac{7 \times 2 \times 2}{2 \times - 3} = \frac{14}{ - 3} [/tex]
