How do i write: Three sets of a number and four are added to the sum of seven times the same number and thirteen

As a equation it would look something like this 7x+13+3x+4 however depending on how the questions looks it could also be something like this I would think 7x+13+3x+4 but my first answer seems like the best guess for me.

As an equation is would look lik dis 7x+13+3x+4