Find the slope of the line passing through the given points
There aren't any given points.
Graph each line
They're in the attachments.
Why do you think that the slope of a vertical line is called "undefined?"
It's undefined because the line goes straight up and down and we cannot measure the slope. Plus, if we try to plug in two points on the line, we get 0 at the end of our fraction, and we cannot divide by 0.
Can you find the equation of a line if you are given the slope and the x-intercept? If so, explain how. If not, explain why you can't.
Yes, we can plug the x-intercept and the slope into point-slope form(y - y1 = m(x - x1)) and simplify to slope-intercept form if needed.