The Earth is titled at an angle of 23.5 degrees on its axis, so sunlight reaches different parts of the planet at different times. Distance from the sun causes climate to change, which causes seasons. If the Earth is directly facing the sun, it’s most likely summer in that region.
If you multiply (x - k)(x + k), you get which is equal to . Now you can see that must be equal to which is equal to . Now we just need to solve . The final answer is .