7-3 Writing equations in Slope- Intercept form Objectives: Write a linear equation in Slope-intercept form given the slope and y intercept

Questions What is the format for slope intercept form? What do the variables “m” and “b” mean and what do they tell you? What part of the graph will you find “b”, what axis? What’s do you do after you have plotted “b” If you are given only 2 points, describe the steps to placing the equation in slope intercept form.

Linear Equations (y = mx + b) b = y-intercept plot (0,b) to get your first point m = slope written as a fraction slope = rise / run Lean right if positive Lean left if negative

7-3 Slope intercept form: y=mx+b The y coordinate Slope rise/run The x coordinate The y intercept, Where it crosses the y line

Linear Equations (y = mx + b) y = 1 / 3 x - 3 m = 1 / 3 (slope rise / run ) positive leans right plot up 1, right 3 plot down 1, left 3 connect the points b = -3 (y-intercept) plot (0,-3)

Linear Equations (y = mx + b) y = - 1 / 2 x + 2 m = - 1 / 2 (slope rise / run ) negative leans left plot up 1, left 2 plot down 1, right 2 connect the points b = 2 (y-intercept) plot (0,2)

7-3 Given the slopem and the y interceptb write an equation in slope intercept form m= -3 b= -2 Step1: write the equation Step 2: substitute the given numbers

7-3 The equation can then be graphed y= -3x-2 b=-2 m= -3 y=-3x-2

7-3 Sometimes you may have to manipulate the equation to get it in slope-intercept form 4x-2y=8 Subtract the 4x from both sides Divide all by -2 to isolate y

Given two points, write the equation of a line in slope intercept form Steps: 1. Find slope 2. Place a point and the slope in into point slope form 3. Distributive property 4. Additive property of equality GIVEN: (2,-3) and (4,-2)