To find the equatiom of the graph, we must find the y-intercept and the slope of the line.
Find the y-intercept:
- To find the y-intercept, simply look at the point of where the line crosses the y-axis. In this case, the line seems to cross the point at (0,4), giving the y-intercept of equaling 4.
Find the slope:
- To find the slope of the line, take one of the points and use the "rise/run" method, and find the next consecutive point. In this case, we'll take point (4,1) as an example. The next consecutive point is @ (0,4). So, we'll count 3 units up and 4 units left. So the slope of this line will be -3/4. (It is negative because we counted to the left. However, POSITIVE 3/4 would have left us with an entirely different slope and the line would be structurally different ((Seriously, try it out for yourself, if you don't understand what I am talking about!))).
Now that we have our slope and y-intercept, let's use the slope-intercept form so that we can get our equation.
- Slope-Intercept Form:
• y = mx + b
□ Whereas, "m" equals the slope of the line, and "b" equals the y-intercept of the line.
- Let's plug in the values of the y-intercept and the slope into the equation.
** y = -3/4x + 4 **
So, the equation for this line is "y = -3/4x + 4".
