A two dimensional linear equation is of the form ax+by+c = 0 . It is in two variables x and y. The equation is if degree one.

The other linear form is y = mx+c which is a slope intercept form, where m is the slope of the line with respect to x axis and c is the y intercept.

The double intercept form of the of the linear equation is x/a+y/b = 1, where and b are the intercepts on x and y axis.

If a line passes through the two points (x1,y1) and (x2,y2), then the the equation of the line is y-y1 = {(y2-y1)/(x2-x1))}(x-x1).

1) We'll start with the general form of the linear equation:

Ax + By + C = 0

A,B,C, are constants and the major constraint is: A,B are not equal to zero.

2) We'll continue with the most common form of the linear equation, namely the standard form :

y = mx + n, where m is the slope of the straight line and n is the y intercept.

3) We'll give another form of the linear equation: the point slope form, that is useful when we know the slope of the line and the coordinates of a point located on the line:

y - y1 = m(x - x1)

m is the slope

(x1 , y1) are the coordinates of the point located on the slope.

4) Another form of the linear equation is the intercept form:

x/a + y/b = 0, where a and b represent the x axis and y axis intercepts of the line.

5) If the line is passing through 2 known points, then the equation of the line is:

(x2 -x1)/(x - x1) = (y2 - y1)/(y - y1)

6) The parametric form of the line;

x = U + t*T

y = W + t*V

m = V/T,

(VU−WT) / V is x intercept and

(WT−VU) / T is y intercept