The general form for a linear equation in two dimensions is

**y** =

*m***x** +

*b*, where

*m* is a

real constant representing

slope, and

*b* is a

real constant representing the

y-intercept.

Expressed in point-slope form, a linear equation in two dimensions may be written as **y** - *y*_{1} = *m*(**x** - *x*_{1}), where *m* is again the slope of the line, and (*x*_{1}, *y*_{1}) is a point in the line.