Five years ago, david was three times as old as julia was. in 2 years, david will be twice as old as julia will be. how old is david now?

These sentences can be rewritten as the mathematical equations, d-5=3 (j-5) and d+2=2 (j+2). Solving both equations for d gives, d=3j - 10 and d = 2j + 2. You can now set the right hand side of these equations equal to each other and solve for j to find that j=12. Substituting 12 for j in any of the equations, gives you Dave's age, d = 26.