All that remains to be done is to find out whether the conclusion of the argument follows from its premises. If it does, then the argument is valid. Otherwise, it is invalid. Clearly, the argument in question is valid. Let's try one more example.
Some schools are educational institutions.
Some schools are colleges. Some colleges are educational institutions. To represent the first premise of this argument, we need to show that something is in the area of schools that are educational institutions. So we need to place a lowercase x in both areas and draw a line between them. Some schools are educational institutions.