Horizontal compression by factor 2 will do following.
After compression graph of the function is going to be closer to line of symmetry of the parabola. Values of y are not going to change, but values of x will be 2 times closer to the the line of symmetry.
For our case , line symmetry x=2,
points are going to be 2 times closer to this line.
1st point (4, -3) converts into (3,-3)
2nd point (-4,5) converts into (-1,5)