Explicație pas cu pas:
4.a)
[tex] \frac{7}{8} \times \frac{2}{5} =\frac{7}{2 \times 4} \times \frac{2}{5}= \frac{7}{20} [/tex]
b)
[tex] \frac{36}{44} \times \frac{11}{12} =\frac{3 \times 12}{4 \times 11} \times \frac{11}{12} = \frac{3}{4} [/tex]
c)
[tex] 3\frac{12}{16} \times \frac{4}{10} = 3\frac{3}{4} \times \frac{2}{5} = \frac{15}{4} \times \frac{2}{5} = \frac{3 \times 5}{2 \times 2} \times \frac{2}{5} = \frac{3}{2} [/tex]
d)
[tex]2 \frac{1}{4} \times 1 \frac{23}{45} = \frac{9}{4} \times \frac{68}{45} = \frac{9}{4} \times \frac{4 \times 17}{9 \times 5} = \frac{17}{5} [/tex]
5.a)
[tex] \frac{7}{16} \div \frac{9}{16} = \frac{7}{16} \times \frac{16}{9} = \frac{7}{9} [/tex]
b)
[tex]- \frac{11}{28}\div\frac{33}{56} = - \frac{11}{28} \times \frac{2 \times 28}{3 \times 11} = - \frac{2}{3} [/tex]
c)
[tex]3 \frac{3}{4} \div ( - 2 \frac{11}{12}) = \frac{15}{4} \div ( - \frac{35}{12}) = - \frac{3 \times 5}{4} \times \frac{3 \times 4}{5 \times 7} = - \frac{9}{7} [/tex]
d)
[tex]( - 24) \div ( - 5 \frac{7}{13}) = ( - 24) \div ( - \frac{72}{13}) = 24 \times \frac{13}{3 \times 24} = \frac{13}{3} [/tex]
