1) from the given figure
There is a line that passes through points (2, 1) and (0, -3)
The rule of the slope of a line passes through two points on a line
(x1, y1) and (x2, y2) is
x1 = 2 and y1 = 1
x2 = 0 and y2 = -3
Substitute them in the rule of the slope to find it
The slope of the line is 2
Very important notes about the slope
1. The slope of the vertical line (parallel to the y-axis) is undefined
2. the slope of the horizontal line (parallel to the x-axis) is zero