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.