Why is 9 a square number:

1 x 1 is 2
2 x 2 is 4
4 x 4 is 8
8 x 8 is 16

so how is 9 a square number : (

Use the elimination method to find the solution to the system of equations. 2x - 3y = -9 -x + 3y = 6

The marriott family bought a new apartment three years ago for $65,000. the apartment is now worth $86,515. assuming a steady rate of growth, what was the yearly rate of appreciation? what is the percent of the yearly rate of appreciation?

Sketch one cycle if the cosine function y=2cos2theta