Answer:
It has no slope because (x2-x1) in the formula [tex]m=\frac{y2-y1}{x2-x1}[/tex] is equal to zero, and the denominator of a fraction cannot be zero
Step-by-step explanation:
we know that
The formula to calculate the slope between two points is equal to
[tex]m=\frac{y2-y1}{x2-x1}[/tex]
we have
the points (7, 10) and (7, 20)
substitute the values
[tex]m=\frac{20-10}{7-7}[/tex]
[tex]m=\frac{10}{0}[/tex] ----> is undefined
The line has a slope undefined ---> is a vertical line (parallel to the y-axis)