The slope of a line can be calculated using the following formula:
[tex]m=\frac{y_2-y_1}{x_2-x_1}[/tex]In this case, you know that the following points are on the line mentioned in the exercise:
[tex]\begin{gathered} \mleft(7,-3\mright) \\ \mleft(5,1\mright) \end{gathered}[/tex]Then, you can set up that:
[tex]\begin{gathered} y_2=1 \\ y_1=-3 \\ x_2=5 \\ x_1=7 \\ _{} \end{gathered}[/tex]Knowing these coordinates, you can substitute them into the formula and the evaluate. Therefore, you get that the slope of this line is:
[tex]\begin{gathered} m=\frac{1-(-3)}{5-7} \\ \\ m=\frac{1+3}{-2} \\ \\ m=\frac{4}{-2} \\ m=-2 \end{gathered}[/tex]The answer is:
[tex]m=-2[/tex]