It is because of their humid continental climates. Warm hot summers and cold winters.
The geographic theme of movement conveys how people and places are connected
First off you should really type the equation in the proper order and also use the carat symbol to show that something is to the power too, so your equation shouldve looked like this.
-y^2 -4y + 4 = 0
But all yuo need to is plug the equation into a calculator and search for where it intersects the X line. the answers are
(.828, 0) , (-4.83, 0)