if the slope "m" and the y-intercept "b" are both 0, then the slope-intercept form of it could just be written as
y = 0x + 0
which of course is just y = 0.
now, is (-1,0) on the line y = -4x -1?
well, to find the other coordinate, we can simply plug in the known coordinate value, say hmmm if we set x = -1, do we get 0 for "y"? let's check
y = -4(-1) - 1
y = 3.................................. for the point (-1, 3)
whatever happened to Margo? well, we gather she used x = 0, y = -4(0) - 1, y = -1, and that gives the point (0, -1) NOT (-1, 0).
so her mistake is, she used the y-coordinate value of 0 and used it on the "x" value to get the -1.l
however (-1, 0) is not on the line, but (0, -1) is.
