1. Slope-Intercept Form

2. y=mx + b m is the SLOPE m is the SLOPE b is the Y-INTERCEPT (where the line crosses the y-axis) b is the Y-INTERCEPT (where the line crosses the y-axis) the “x” and “y” must be present at the end within the equation to graph the line the “x” and “y” must be present at the end within the equation to graph the line

3. Slope-Intercept Form of the Equation of a Line The line with slope “m” and y-intercept has the equation y = m x + b. y=3x-6 y=3x-6 The slope is 3 The slope is 3 The y intercept is -6 The y intercept is -6

4. Writing an Equation Write the equation of the line with slope 3/8 and y-intercept 5. Use slope intercept form: y = mx + b Substitute in for m and b

5. Writing an Equation y = 3/8 x + 5

6. What if I’m Given the Slope and an Ordered Pair to form a slope-int equation m = 3, (5,-2) m = 3, (5,-2) y = mx + b y = mx + b y = 3x + b y = 3x + b y = 3(5) + b y = 3(5) + b -2 = 3(5) + b -2 = 3(5) + b Solve Solve -2 = 3(5) + b -2 = 15 + b -15 -15 -17 = b Therefore the equation is: y = 3x -17

7. What If I’m Given Two Ordered Pairs? Write an equation in slope-intercept form of a line passing through each pair of points. Write an equation in slope-intercept form of a line passing through each pair of points. Step One – Find the slope Step One – Find the slope Step Two – Input one set of ordered pairs into the slope intercept form and solve for b (y – int) Step Two – Input one set of ordered pairs into the slope intercept form and solve for b (y – int)

8. You Try Write the equation of a line with slope -.5 and y-intercept -3 y = Write the equation of a line with slope 4 and y-intercept -5/2. y =

9. You Try Identify the slope and y intercept. y = -5x + 13 Slope:Y-Intercept: Identify the slope and y intercept. y = 1/4x – 2 Slope:Y-Intercept:

10. You Try Write the equation of a line with slope -3 that passes through pt. (2, 5)

11. Example: Write these Two Ordered Pairs in Slope Intercept Form (-4, 4) and (2, 1) (-4, 4) and (2, 1) 4 -1 = 3 or 1 4 -1 = 3 or 1 -4 -2 = -6 or -2 -4 -2 = -6 or -2 Input slope into the formula with one set of ordered pairs y 2 – y 1 x 2 – x 1 Formula for Slope Slope Intercept Form: y = mx + b 1 = -1/2 (2) + b 1 = - 1 + b +1 +1 2 = b Therefore: y = -1/2x + 2 Solve