Question

Exercițiile 1 si 2 de la aplica ce ai învatat

Answer 1

1)a)
$\frac{2}{5} + \frac{3}{4} = \frac{4 \times 2 + 5 \times 3}{20} = \frac{8 + 15}{20} = \frac{23}{20}$
B)
$\frac{3}{7} \times ( \frac{2}{5} + \frac{3}{4} ) = \frac{3}{7} \times \frac{23}{20} = \frac{69}{140}$
C)
$\frac{3}{7} \times \frac{2}{5} = \frac{6}{35}$
D)
$\frac{3}{7} \times \frac{3}{4} = \frac{9}{28}$

E)
$\frac{3}{7} \times \frac{2}{5} + \frac{3}{7} \times \frac{3}{4} = \frac{3}{7} \times ( \frac{2}{5} + \frac{3}{4} ) =$
$\frac{3}{7} \times \frac{23}{20} = \frac{69}{140}$

2)
$\frac{5}{4} \times ( \frac{1}{3} - \frac{1}{2} ) = \frac{5}{4} \times \frac{1}{3} - \frac{5}{4} \times \frac{1}{2}$
$\frac{5}{4} \times ( \frac{2 - 3}{6} ) = \frac{5}{12} - \frac{5}{8}$
$\frac{5}{4} \times ( - \frac{1 }{6} ) = \frac{8 \times 5 - 12 \times 5}{96}$
$- \frac{5}{24} = \frac{40 - 60}{96}$
$- \frac{5}{24} = - \frac{20}{96}$
-20/96:4= - 5/24 =>
$- \frac{5}{24} = - \frac{5}{24}$