Question

Ayudeme con este ejercicio xfavor

Answer 1

Giuma,
Vamos paso a paso

         21/5 de 1/7
                        = 21*1/5*7
                        = 21/35

          5/7 de 21/35
                        = 5*21/7*35
                        = 105/245
                        = 105:35/245:35
                        = 3/7  RESULTADO FINAL
                                                        ALTERNATIVA e)

Answer 2

$Calcula \ los \ \dfrac{5}{7}\ de \dfrac{21}{5}\ de \ \dfrac{1}{7}= \\ \\ Se \ realiza\ una \ multiplicaci\'on \\ \\ \\ \dfrac{5}{7}\ *\dfrac{21}{5}\ * \ \dfrac{1}{7}= \dfrac{5*21*1}{7*5*7} = \dfrac{105}{245} = \boxed{ \dfrac{3}{7} } \to e)$

Espero que te sirva, salu2!!!!