1)a)
[tex] \frac{2}{5} + \frac{3}{4} = \frac{4 \times 2 + 5 \times 3}{20} = \frac{8 + 15}{20} = \frac{23}{20} [/tex]
B)
[tex] \frac{3}{7} \times ( \frac{2}{5} + \frac{3}{4} ) = \frac{3}{7} \times \frac{23}{20} = \frac{69}{140} [/tex]
C)
[tex] \frac{3}{7} \times \frac{2}{5} = \frac{6}{35} [/tex]
D)
[tex] \frac{3}{7} \times \frac{3}{4} = \frac{9}{28} [/tex]
E)
[tex] \frac{3}{7} \times \frac{2}{5} + \frac{3}{7} \times \frac{3}{4} = \frac{3}{7} \times ( \frac{2}{5} + \frac{3}{4} ) = [/tex]
[tex] \frac{3}{7} \times \frac{23}{20} = \frac{69}{140} [/tex]
2)
[tex] \frac{5}{4} \times ( \frac{1}{3} - \frac{1}{2} ) = \frac{5}{4} \times \frac{1}{3} - \frac{5}{4} \times \frac{1}{2} [/tex]
[tex] \frac{5}{4} \times ( \frac{2 - 3}{6} ) = \frac{5}{12} - \frac{5}{8} [/tex]
[tex] \frac{5}{4} \times ( - \frac{1 }{6} ) = \frac{8 \times 5 - 12 \times 5}{96} [/tex]
[tex] - \frac{5}{24} = \frac{40 - 60}{96} [/tex]
[tex] - \frac{5}{24} = - \frac{20}{96} [/tex]
-20/96:4= - 5/24 =>
[tex] - \frac{5}{24} = - \frac{5}{24} [/tex]
