How does continentally affect the weather of a region?

Continentality, a measure of the difference between continental and marine climates characterized by the increased range often peratures that occurs over land compared with water. This difference is a consequence of the much lower effective heat capacities of land surfaces as well as of their generally reduced evaporation rates.

because the center-south is called the heart of the country

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

b = (5, -4)