ANSWER
James made 3 free throws and 4 three-point baskets.
EXPLANATION
We want to find the number of free throws and three-point baskets James made.
Let the number of free throws be f.
Let the number of three-point baskets be b.
James made a total of 7 baskets.
This means that:
Each free throw is worth 1 point and each three-point basket is worth 3 point.
The total number of points he had is 15 points.
This means that:
We now have a system of simultaneous equations:
From the first equation:
Substitute that into the second equation:
Substitute that into the equation above:
Therefore, James made 3 free throws and 4 three-point baskets.