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:
[tex]f+t=7[/tex]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:
[tex]f+3t=15[/tex]We now have a system of simultaneous equations:
[tex]\begin{gathered} f+t=7 \\ f+3t=15 \end{gathered}[/tex]From the first equation:
[tex]f=7-t[/tex]Substitute that into the second equation:
[tex]\begin{gathered} 7-t+3t=15 \\ 7+2t=15 \\ \Rightarrow2t=15-7=8 \\ t=\frac{8}{2} \\ t=4 \end{gathered}[/tex]Substitute that into the equation above:
[tex]\begin{gathered} f=7-4 \\ f=3 \end{gathered}[/tex]Therefore, James made 3 free throws and 4 three-point baskets.