If your screen is not partitioned into three frames, press here to bring up the frames that will enable you to use this quiz. The graph of any equation in two variables is a straight line. The graph of any linear equation in two variables is a straight line.
Every straight line has a slope.
Every line is the graph of a linear equation in two unknowns. To find the equation of a line, all you need is a point and the slope. You need to know the y-intercept to write down the equation of a line. In a linear cost function, the slope gives the cost of the first item. If displacement is a linear function of time, then the slope of the graph represents the velocity.