Hi there!
The formula for finding the slope of a line, which has coordinates [tex](x_{1},y_{1})[/tex] and [tex](x_{2},y_{2})[/tex] is:
[tex]m=\frac{y_{2}-y_{1}}{x_{2}-x_{1}}[/tex]
It doesn't matter which set of points you make [tex](x_{1},y_{1})[/tex] or [tex](x_{2},y_{2})[/tex], but you must apply it to the formula correctly.
For this case, I will use the point [tex](4,7)[/tex] as [tex](x_{1},y_{1})[/tex], and [tex](-6,7)[/tex] as [tex](x_{2},y_{2})[/tex].
[tex]m=\frac{y_{2}-y_{1}}{x_{2}-x_{1}}[/tex]
[tex]m=\frac{7-7}{-6-4}[/tex]
[tex]m=\frac{0}{-10}=0[/tex]
This means that the slope of the line passing through [tex](4,7)[/tex] and [tex](-6,7)[/tex] is [tex]0[/tex].
Hope this helps! :^)
