Question

3) Calcule as multiplicações, observando que
agora são expressões.
a) (-1/2). (+2/3) - (-3/7) =
b) (-2/5).(-3/2).(-8/5) =
c) (-1/2). (-1/2).(-1/2) =
d) (-1).(+5/3). (+3/5) =
e) (+7).(-1/7).(+7) =​

Answer 1

Explicação passo-a-passo:

.

$( - \dfrac{1}{2} ) \times ( \dfrac{2}{3} ) - ( - \dfrac{3}{7} )$

$- \dfrac{2 }{6} + \dfrac{3}{7}$

$\dfrac{ - 14 + 18}{42}$

$\dfrac{4 \div 2}{42 \div 2}$

$\dfrac{2}{21}$

.

$- \dfrac{2}{5} \times - \dfrac{3}{2} \times - \dfrac{8}{5}$

$- \dfrac{48 \div 2}{50 \div 2}$

$- \dfrac{24}{25}$

.

$- \dfrac{1}{2} \times - \dfrac{1}{2} \times - \dfrac{1}{2}$

$- \dfrac{1}{8}$

.

$- 1 \times \dfrac{5}{3} \times \dfrac{3}{5}$

$- \dfrac{15}{15}$

$- 1$

.

$7 \times - \dfrac{1}{7} \times 7$

$- \dfrac{49}{7}$

$- 7$