Need help with this, find the side of X

Idon’t understand! use slope intercept form to solve: through: (2,5) slope= undefined

The equation line of cd is y=-2x-2. write an equation of a line parallels to line cd in slope-intercept form that contains point (4,5)

Three runners competed in a race data were collected at each mile mark for each runner if the runner ran at a constant pace the data would be linear