y=x？ The intersection of -2x and x axis is 0 and 2.

It is known that 2 and -2 are symmetric about y.

So y=x? +2x and y=x? -2x images are symmetric about y.

2.y=x？ -4x+5=(x-2)？ + 1

So y=x? The equation of symmetry axis of -4x+5 image is x=2.