Respuesta :

2:4/5
= 2/(4/5)
= 2*(5/4)
= 5/2
= 5:2

3/4:3/10
= (3/4)/(3/10)
= (3/4)*(10/3)
= 5/2
= 5:2

Because 5:2= 5:2, 2:4/5 and 3/4:3/10 form a proportion~