Respuesta :

Jelly is 21 years old.
Mary is: x + 6
Jelly is x
Their sum is 48

x + x + 6 = 48
2x + 6 (-6) = 48 (-6)
2x = 42
2x/2 = 42/2
x = 21

Jelly is 21 years old
Mary is 27 years old

hope this helps