Hello, there.
To find the slope of a line, first you need to make sure which points this line passes through:
The slope [tex]m[/tex] of a line, passing through the points [tex](x_0,~y_0)[/tex] and [tex](x_1,~y_1)[/tex] is given by the formula [tex]m=\dfrac{y_1-y_0}{x_1-x_0}[/tex].
As we can see in the graph, this lines passes through the points [tex](0,~1)[/tex] and [tex](1,~3)[/tex], such that we can substitute these values on the formula to find its slope:
[tex]m=\dfrac{3-1}{1-0}[/tex]
Subtract the values in both numerator and denominator
[tex]m=\dfrac{2}{1}=2~~\checkmark[/tex]
This is the slope of this line.
