SOLUTION: Why is it not possible to write the equation of the line through (-8, -5) and (-8, -9) in point-intercept form?

Algebra ->  Linear-equations -> SOLUTION: Why is it not possible to write the equation of the line through (-8, -5) and (-8, -9) in point-intercept form?      Log On


   

Question 501950: Why is it not possible to write the equation of the line through (-8, -5) and (-8, -9) in point-intercept form?
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!

First let's find the slope of the line through the points and


Note: is the first point . So this means that x%5B1%5D=-8 and y%5B1%5D=-5.
Also, is the second point . So this means that x%5B2%5D=-8 and y%5B2%5D=-9.


m=%28y%5B2%5D-y%5B1%5D%29%2F%28x%5B2%5D-x%5B1%5D%29 Start with the slope formula.


m=%28-9--5%29%2F%28-8--8%29 Plug in y%5B2%5D=-9, y%5B1%5D=-5, x%5B2%5D=-8, and x%5B1%5D=-8


m=%28-4%29%2F%28-8--8%29 Subtract -5 from -9 to get -4


m=%28-4%29%2F%280%29 Subtract -8 from -8 to get 0


Remember, you cannot divide by zero. So this means that the slope is undefined.


Since the slope is undefined, this means that the equation of the line through the points and is x=-8.


Any equation in the form x = k where k is some number CANNOT be written in the form y-y%5B1%5D=m%28x-x%5B1%5D%29, which is why it is not possible to write the equation of the line through (-8, -5) and (-8, -9) in point-intercept form.