If AB= x+3, EF= x+7, and DC= 2x-1, then x=? , AB=? , EF=? , and DC=?

I am in Fifth grade but in 6th grade math. According to the problem, the only way to figure out what anything means or equals, you would need to solve x. Since x is a variable, it can be any number. Therefore, you can make x anything you want. let's say for now that x =3. then AB=6, EF= 10, and DC=5. Voila!