# Write an equation for a graph

We will assign a number to a line, which we call slope, that will give us a measure of the "steepness" or "direction" of the line. It is often convenient to use a special notation to distinguish between the rectan- gular coordinates of two different points. We can designate one pair of coordinates by x1, y1 read "x sub one, y sub one"associated with a point P1, and a second pair of coordinates by x2, y2associated with a second point P2, as shown in Figure 7. Note in Figure 7. Math, Science, and History Teacher Tutor Without seeing the graph, I can't help you get the exact answer, but I can give you some tips that might help you. Since you stated that the graph is a diagonal line, I know that you are looking for a linear equation.

To get the exact equation, we need to find the values of m and b you will keep th1. The sign on the m value slope of the line is determined on whether it goes up or down as you go to the right. If the line goes up to the right, m is positive. If the line goes down to the right, m is negative.

Assuming you can see the x and y-axis with hash marks bold vertical and horizontal lines with small marks evenly spaced along themyou can find the vlaue of m the slope of the line.

The slope is found by counting how much the line moves up or down through a distance moving right to left. For example, you might find that at one point of the line you are one mark above the x-axis and two marks right of the y-axis. Moving along the line, you may find that you are four marks above the x-axis and four marks above the y-axis.

The slope is found by comparing the change in height 1 mark up goes to 4 marks up and the change in length 2 marks goes up to 4 marks. If you can see the where the line crosses the y-axis bold vertical lineyou have your b value.

If you can't see where the line crosses the y-axis, you can still find the value of b. Just find a point on the line. Write the slope intercept form of the equation with the values that you found for m and b. One other quick tip: If you have hashes on your x-axis and y-axis, but there are no numbers written, assume that each hash represents 1.Make sure the linear equation is in the form y = mx + b.

This is called the y-intercept form, and it's probably the easiest form to use to graph linear equations. Students are asked to write and solve a two-step equation to model the relationship among variables in a given scenario. The graphs of any two solutions of an equation in two variables can be used to obtain the graph of the equation.

However, the two solutions of an equation in two variables that are generally easiest to find are those in which either the first or second component is 0. Improve your math knowledge with free questions in "Write a linear equation from a graph" and thousands of other math skills.

Now, since you have two parameters (a and b), just use two of the data points of your graph; this leads to two linear equations you can simply solve. Just use the third data point to . A line has a slope of negative 3/4 and goes through the point 0 comma 8.

What is the equation of this line in slope-intercept form? So any line can be represented in slope-intercept form, is y is equal to mx plus b, where this m right over here, that is of the slope of the line. How To Solve Y=mx+b