Objective The student will be able to: graph a line given any linear equation. SOL: A.6 Designed by Skip Tyler, Varina High School

There are 3 different methods used for graphing equations. 1)using slope-intercept form 2)using x- and y-intercepts 3)using a t-table

Graphing with slope-intercept form: Use this form when your equation is already solved for y. Example: Graph m =, b = 2 1.Start by graphing the y-intercept (b). 2.From the y-intercept, do “rise over run” using your slope. Repeat this again from your new point. 3.Draw a line through your points.

3 Start at the y-intercept (2), down 1, over 3 (because slope was ). Start here

Graphing with x- and y-intercepts: Use this form when your equation is already in standard form. Example: Graph -2x + 3y = 12 1.Find your x-intercept: Let y = 0 (or remember C/A) x = -6; (-6, 0) 2.Find your y-intercept: Let x = 0 (or remember C/B) y = 4; (0, 4) 3.Graph both points and draw a line through them.

Plot (-6, 0) and (0, 4). Connect the dots!

Graphing using Intercepts Remember, if your x- and y-intercepts are both zero that will only give you one point. Use the slope to get another point. Graph: 2x – 3y = 0 x-int: C/A = 0/2 = 0 y-int: C/B = 0/-3 = 0 Since the x- and y-intercepts are both at the origin you need a way to get another point. It takes two points to graph a line.

2x – 3y = 0 You can put the equation in slope-intercept form to find the slope. y = (2/3)x or Remember the slope is x y

Graphing with a t-table: Use this form for any equation. Example: Graph -x + y = 2 1.Solve the equation for y. y = x Create a table with at least 3 values for x. 3.Plug x into the equation to find y. 4.Graph your ordered pairs and draw your line.

Complete your t-table using the domain {0, 1, 2}. 2 (0, 2) 3 (1, 3) 4 (2, 4) x y 0 1 2