The are a few different ways to find the equation of a line; using the slope-intercept formula is one of the most common. Remember the formula y = mx + b? We love lines in this form (y=mx + b ) because it’s very easy to graph them- we just use the slope (m) and the y-intercept (b) to plot points and draw our line. However our focus here is not to graph a line rather we want to find the equation of a line (y= mx + b ) given some information about it. So what type of information about a line do we need to know to find it’s equation? The answer is we need to either have two (x, y) points that are on the line or one (x, y) point on the line and the slope of the line. When you have the slope (m) and at least one point- just follow the steps below to see how we get the equation of the line. Now what if we just have two points on the line and not the slope? No need to panic just use the two points you have to calculate the slope and then use one of those points- follow the steps below and you will be good to go!
some key topics that involve slope-intercept formula:
* linear equations
* writing linear equations
* point-slope formula
* SAT and ACT exams
* college prep math and science courses