If five more than twice a number is seventeen, then just twice the number is five less than seventeen. So, twice the number is seventeen minus five, which is twelve. Twice the number is twelve. Now, to find the number by itself, we need to divide twelve by two. So, the number is six.
We can check our answer like this: is five more than six times two seventeen?? Well, six times two is twelve. Five more than twelve is seventeen. So, we are right.