Let's comment the system. We can see that the first equation is
. It means that x and y are two quantities that sum to 27. Since we know that the team scored a total of 27 baskets, we know that x and y are something that "compose" the number of baskets. So, they must be the number of two and three points shot.
The second equation is
. We know that the team scored 60 points, and that every x is "worth" 2 and every y is "worth" 3. So, x is the number of two-points shots and y is the number of three points shots.
To solve the system we can isolate y from the first equation:
and substitute this expression in the second equation:

So, we can deduce back
Now remember that x was the number of two-points shots and y was the number of three-points shots to get to the answer.