In algebra, linear equations means you're dealing with straight lines. When you're working with the xy-coordinate system, you can use the following formulas to find the slope, y-intercept, distance, and midpoint between two points.
Consider the two points (x1, y1) and (x2, y2):
Slope of the line through the points:
![image0.png](https://www.dummies.com/wp-content/uploads/425926.image0.png)
Slope-intercept form of the line with y-intercept b:
![image1.png](https://www.dummies.com/wp-content/uploads/425927.image1.png)
Point-slope form of the line with slope m:
![image2.png](https://www.dummies.com/wp-content/uploads/425928.image2.png)
Distance formula:
![image3.png](https://www.dummies.com/wp-content/uploads/425929.image3.png)
Midpoint formula:
![image4.png](https://www.dummies.com/wp-content/uploads/425930.image4.png)