First, larger the number (ignoring any minus signs) the steeper the line. Thus, we can use the slope to tell us something regarding just how steep a line is.
Next, if the slope is a +ve number then the line will be rising as we move from left to right. Similarly, if the slope is a -ve number then the line will decrease as we move from left to right.
We can employ the final two parts to see what the slopes of horizontal & vertical lines will be. A horizontal line will always contain a slope of zero & a vertical line will always have an undefined slope.
Now we have to take a look at some special forms of the equation of the line.
We will begin with horizontal & vertical lines. A horizontal line along a y-intercept of b will have the equation,
y = b
Similarly, a vertical line along with an x-intercept of a will have the equation,
x =a