Question 10815
x = Grace age
2x = Roz age

x+5+2x+5 = 28
3x + 10  = 28
     3x  = 28 - 10
      x  = 28/3
      x  = 6
 
    x = 6 
 2(6) = 12
 
 Roz is 12 years old
 Grace is 6 years old