Linear equation

In mathematics, a linear equation is a type of equation. A linear equation is the equation of a straight line. This type of equation is written in the form:
formula_1
or formula_2 also known as rise over run.
The m is the rate of change or slope. 
The slope is how fast the line moves up or down. Numbers farther from 0, or a larger absolute value 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. 
While b is 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.
You can find the slope of a graph by seeing how much the y-value increases by for every one x-value. You can find the y-intercept of a graph by looking at where the x coordinate equals 0, and see what the y-value equals.