Question

caucule a) 1/3 x 4/7 b)7/8 x3/2 c) 3/5 x 5/9 d) 2/7x11/2 e)7/11 x 11/7 f) 13/10 x10/13 g)8/9 x 45/4 4/45x9/8

Answer 1

Multiplica-se posição por posição, brother!
a)
$\frac{1}{3} \times \frac{4}{7} = \frac{4}{21}$
b)
$\frac{7}{8} \times \frac{3}{2} = \frac{21}{16}$
c)
$\frac{3}{5} \times \frac{5}{9} = \frac{15}{45} = \frac{1}{3}$
d)
$\frac{2}{7} \times \frac{11}{2} = \frac{22}{14} = \frac{11}{7}$
e)
$\frac{7}{11} \times \frac{11}{7} = \frac{77}{77} = 1$
f)
$\frac{13}{10} \times \frac{10}{13} = \frac{130}{130} = 1$
g)

$\frac{8}{9} \times \frac{45}{4} \times \frac{4}{45} \times \frac{9}{8} = \frac{360}{36} \times \frac{36}{360} = 1$