In mathematics, a linear equation is a type of equation. In a linear equation, both terms have to be constant. A linear equation is the equation of a straight line. This type of equation is written in the form: y = mx + b OR (y - y1) = m(x - x1) WHERE m = the rate of change, or slope. The slope is how fast the line moves up or down. Larger numbers will make the slope steeper. If m is a negative number, then the line will appear to fall or go down the page when read from left to right. If m is a positive number, then the line will appear to climb the page when read from left to right. b = the y-intercept of the function. This is where the function crosses the y - axis of the coordinate plane. The first equation is called slope-intercept form, because in it, the slope (m) and y-intercept (b) are easily found. The second equation is called point-slope form, because in it, a point on the graph (x1, y1) and the slope (m) are easily found.