Question

sejam a=-13 7, b=-9-21, c=-3/4 2/3 e d=4*(-5/8). qual o valor da expressao a/b / b/c

Answer 1

a = 7 - 13 = - 6 
b = -9 - 21 =  -30 
c = 3/4 * 2/3 = 6/12 = -1/2 
d = 4 * (-5/8) = -5/2 
Logo
a/b = -6/-30 = 5
b/c = -30/(-1/2) = 60
a/b/b/c = 5/60 = 1/12 

Answer 2

a = -13 + 7 = -6 

b = -9 - 21 =  -30 

c = $\dfrac{-3}{4} * \dfrac{2}{3} = \dfrac{-6}{12} = \dfrac{-\not 6}{\not 12} = \dfrac{-1}{2}$


d = $4 * \dfrac{-5}{8} = \dfrac{-5}{2}$


a)

$\dfrac{a}{b} = \dfrac{-6}{30} = 5$

b)

$\dfrac{b}{c} = \dfrac{-30}{1/2} = -60$

c) 

$\dfrac{a/b}{b/c} = \dfrac{5}{-60} = \dfrac{1}{-12}$