Question 164941
x=-1 graphs as a vertical line.  why? for each value of y , x is always -1.  The graph extends to infinity both directions and is parallel to the y-axis, at -1 on the x-axis  plug in a few values and plot them on graph paper say     (-1,0),(-1,4), and (-1,-5)  draw a line thru those points 

any equation with the form x=a will always be a vertical line just as any equation with the form y=b will be a horizontal line.