Help. ​

x²-1=0 aka third one

Note, NSS....the two roots are  are x = -1 and x  = 1

And when x  = 0.....y is negative

Notice that letting x = 0   in the first equation means that y  = -2...this means that the point (0, -2)  should be on the graph....but this point clearly isn't on the graph

And letting x = 0   in the second and fourth equations, means that y is positive.....and that's not possible on the graph when  x = 0

So....the third equation must be correct.....!!!