For the graph x = - 3 find the slope of a line that is parallel to it.

A parallel line has the same slope and the slope intercept form is Y=mx+b x being the slope so that would be y=-3m+b so a parallel lines slope would also be - 3.

The ilne paralell to x=something is x=something else (both are constants)

slope=rise/run

x=-3

it rises infiniley and runs 0 (goes left to right 0)

slope=infinity/0=undefined

the slope is undefined

paralell lines have same slope

so the slope of a paralell line is also undefined