Lines of longitude include: * 0 points
equator and international date-line
prime meridian and equator
tropic of cancer and arctic circle
prime meridian and 30 degrees east meridian

reflecting point a across the origin negates both of its coordinates.

b = (5, -4)

a and b because with the other three, they simplify to something else.

because the two particles have an equal charge, the charges will cancel out and give the atom an overall charge of 0. so, if at atom has 35 protons in the nucleus, we could expect it to have 35 electrons orbiting that nucleus.