According to economists, this episode of great recession was resulted from a sudden busting of house bubble in US, where the house bubble was caused by rapid growth of improper regulation on sub-prime mortgages (Merriam 2009; Wang 2009; Whitney 2007).
When working with equations that have two variables, the coordinate plane is an important tool. It's a way to draw pictures of equations that makes them easier to understand. To create a coordinate plane, start with a sheet of graph or grid paper. Next, draw a horizontal line.
A relationship between two variables can be described by an equation or a formula. This relationship can be linear, quadratic, square root, or almost any other type of function you can think of. We will focus here on a linear relationship between two variables where one is a constant multiple of the other. This is a special relationship called direct variation. In general, we say that y varies directly as x if there is a constant k so that the equation is true. When graphed, the constant k will be the slope of the line, y = mx + b.