M=undefined passing through P (-7,-4)

M=slope=change in y/change in x=rise/run

it can be undefined when the denomenator is equal to 0

meaning the run or change in x is 0

means the graph doesn't go left or right

means the graph is a vertical line

means the graph is y=c where c is a constant

see the y term

(-7,4)

(x, y)

y=4 is the equation

whenevery you have a slope that is undefined, the equation will be y=c

whenever you have a 0 slope, the equation will be x=c