Linear equations is a preclude to analytic geometry, especially since many analytic geometry concepts are based on the properties of the straight line graph. Linear equations are also important in calculus, especially in calculating the lines of tangency and normals. Here we give a brief overview on linear equations.

Say we have the linear equation y = 2x - 1. The graph, when sketched, will look like:

How do we know? We can calculate values and plot the graph. We can calculate the x- and y- intercepts and sketch from there. But what does the equation tell us?

The general form of the linear equation is

                               y = mx +c

where m is the gradient and c is the y-intercept.

Hence, in the above case, the gradient is 2 and y-intercept is -1. Note that the graph of the linear equation is always a straight line.