Alexa is using a square poster for a project. the area of the square is 36 in2. what is the length of one side of the poster?

To find the answer just find the square root of 36 which is 6. So the length of one side (or actually each side since this is a square) is 6 inches. Hope that helps! 

So the first thing we do is to multiply the top equation by 3. the reason i want to do this is i notice there will be a 6y on both equations and can possibly add/subtract them. so we get 6y = -3x + 27. adding that and the second equation we get 6x = 27-15 which is 12. divide by 6 and we get 2. ∴ x = 2. substituting 2 into the first equation we get 2y = -2 + 9 which is 7. divide by 2 and we get 7/2. ∴ y = 7/2, x = 2.