The point of intersection is when, on a graph, two or more lines meet each other. Let’s start a with a video showing us four separate examples of how to graph a straight line. Keep in mind that you first learned this in grade 9, so let’s consider this as a quick review for you.
Remember that all linear equations have a highest degree of 1. In other words, if your equation contains the independent variable x and the depend variable y, the x variable will never have an exponent greater than 1. Interestingly, later on in the course, we’ll explore non-linear equations whose degree is 2!
Now that you’ve become reacquainted with graphing linear equations without a table, let’s do an example where we exclusively graph two linear equations, then find the point of intersection. It’s important to note that if you are graphing by hand, the point of intersection must be on the grid lines to give an exact answer.
In mathematics, a system of linear equations is a collection of two or more equations involving the same set of variables. If those equations are linear equations, we call them a system of linear equations.
If the equation is written in terms of x and y, as was the case in all the examples above, you’ll have a maximum of 2 equations in the system. If, hypothetically, your equation contained a third variable z, your system would need to have a minimum of 3 equations; however, we won’t be solving equations with 3 variables in this course.