Given the parabola whose equation is , find the focus and determine if the parabola opens up or down.

If the ratio of sum of the first m and n terms of an ap is m2 : n2 , show that the ratio of its mth and nth terms is (2m − 1) : (2n − 1).

Find the solution(s) to the system of equations. select all that apply y=x^2-1 y=2x-2

Percent increase and decrease. original number: 45 new number: 18