Question

4) Calcule:
a) (6/7) : (-9/7)
b) (3/7) : (11/14)
c) (-5/8) : (-9/7)
d) (6/7) : (-9/7)

Answer 1

repete-se a primeira fração e multiplica-se pelo inverso da segunda .
a) (6/7) : (-9/7) = 6/7 .(- 7/9)= -42/63
b) (3/7) : (11/14) =3/7 . 14/11 = 42/77
c) (-5/8) : (-9/7) = -5/8 . ( -7/9) = 35/72
d) (6/7) : (-9/7) = 6/7 . ( - 7/9) = -42/ 63
a letra A e igual a D

Answer 2

a) $\frac{ \frac{6}{7} }{ \frac{-9}{7} } = \frac{6*7}{7*(-9)} = \frac{42}{-63} = - \frac{2}{3}$

b) $\frac{ \frac{3}{7} }{ \frac{11}{14} } = \frac{3*14}{7*11} = \frac{42}{77} = \frac{6}{11}$

c)$\frac{ \frac{-5}{8} }{ \frac{-9}{7} } = \frac{-5*7}{8*(-9)} = \frac{-35}{-72} = \frac{35}{72}$

d)$\frac{ \frac{6}{7} }{ \frac{-9}{7} } = \frac{6*7}{7*(-9)} = \frac{42}{-63} = -\frac{2}{3}$