Question

1) Calcule as expressões :

a) $\frac{1}{2} + \frac{1}{4} . (-\frac{7}{2}) - \frac{5}{4} . (-\frac{1}{8}) =$

b)$(\frac{9}{4} + \frac{7}{2}) + [ \frac{3}{16} . (-10) - \frac{7}{2} =$

2) Determine o valor de A de acordo com o esquema abaixo :

$- \frac{15}{18} + \frac{5}{4} =$
$- \frac{2}{5} + \frac{1}{2} =$ =
MULTIPLICAR OS RESUTADOS = A = ?

Answer 1

1)
a)
$\frac{1}{2}+\frac{1}{4}.(-\frac{7}{2})-\frac{5}{4}.(-\frac{1}{8})=\\ \\ \frac{1}{2}-\frac{7}{8}+\frac{5}{32}=\\ \\ \frac{16-28+5}{32}=\frac{17}{32}$

b)
$(\frac{9}{4}+\frac{7}{2})+[\frac{3}{16}.(-10)-\frac{7}{2}]=\\ \\ (\frac{9+14}{4})+[\frac{3-160}{16}-\frac{7}{2}]=\\ \\ \frac{23}{4}+[\frac{-157}{16}-\frac{7}{2}]=\\ \\ \frac{23}{4}+[\frac{-157-56}{16}]=\\ \\ \frac{23}{4}-\frac{212}{16}=\\ \\ \frac{92-212}{16}=\frac{-120}{16}=-\frac{15}{2}$

c)
a)
$-\frac{15}{18}+\frac{5}{4}=\frac{-30+45}{36}=\frac{15}{36}=\frac{5}{12}$

b)
$-\frac{2}{5}+\frac{1}{2}=\frac{-4+5}{10}=\frac{1}{10}$