# Why Study Math? Linear Equations and Slope-Intercept Form

Linear equations or functions are some of the more basic things studied in mathematics and algebra. The import of these functions is actually they model many real-world phenomena and a key part of them, the slope, is actually a springboard concept for the world of the calculus. That is right: the fundamental idea of rise over slope, or run, within these equations, leads to all sorts of interesting mathematics.

A linear equation, and function, is simply one of the form Ax + By = C. The x and y are actually variables and the a,b, and c represent numbers like one, two, or perhaps three. Usually, the beginning letters in the alphabet represent numbers, or perhaps fixed, quantities and the later letters in the alphabet stand for variables, or changing quantities. We use the words equation or perhaps function interchangeably, though there’s a small difference in meaning. Just the same, the expression Ax By = C is actually known as a linear equation in form that is standard. When we move these expressions around and solve for y, we are able to write this equation as y = A/Bx + C. When we substitute m for B and -a/b for C, we obtain y = mx + b. This latter representation is actually known as slope-intercept form.

The simplicity and utility of this particular form make it special in its own way. The thing is when a linear equation is actually written in this specific form, not only do we have all of the info about the line that we need, but also, we can accurately and quickly sketch the graph. Slope-intercept form, as the title implies, gives us the slope, and inclination, of the line, and the y-intercept, or the point at which the graph crosses the y-axis.

For instance, in the equation y = 2x five, we immediately see that the slope, m, is actually two, and the y-intercept is actually five. What this means graphically is that the line rises two units for every one unit that it runs; this info comes from the slope of two, which may be written as 2/1. From the y-intercept of five, we have a kick-off point on the graph. We locate the y-intercept at (0,5) on the Cartesian coordinate plane, or perhaps graph. Since 2 points determine a line, we go from (0,5) up two units and then to the right one unit. Hence we have the line of ours. In order to make our line somewhat longer so that we are able to draw the picture of its more easily, we may want to go on from the next point and go two more units up and one unit over. We are able to do this as many times as necessary to develop the image of the line of ours.

Linear functions model a lot of real-world phenomena. A basic example would be the following: Suppose you’re a waitress at the neighbourhood diner. You make a fixed twenty dollars per 8-hour shift and the remainder of your revenue is available in the form of tips. After working at this particular job for 6 months, you’ve figured that your average tip income is actually ten dollars per hour. The income of yours could be modelled by the linear equation y = 10x twenty, where x represents hours and y represents income. Therefore for the 8 hour day, you are able to expect to make y = 10(8) twenty or a hundred dollars. You are able to also graph this equation on a coordinate grid using the slope of ten and y-intercept of twenty. You are able to then observe at any point in the day of yours where your income stands.

Simple designs like these show us how mathematics is needed in the world around us. Having read and digested the contents of this article, try to develop the own example of yours of a linear equation or perhaps model. Who knows? You just might start liking math more than ever before. Use these free online calculators to solve your simple and complex mathematical problems.