1. 2-3C Finding an Equation of a Line 2-3C Finding an Equation of a Line Objectives: To write an equation of a line using the slope-intercept equation

2. The Slope-Intercept Equation y = mx + b slope y-intercept Create an equation of a line with a slope of -3 and a y-intercept of 4. y = -3x + 4 y = 4 – 3x 3x = 4 - y -4 = -y – 3x

3. The Slope-Intercept Equation Example 1 y = mx + b Create an equation of a line with a slope of -3 and a y-intercept of 4. y = -3x + 4

4. Example 2 Write an equation for the line with slope 3 that contains the point (-2,4) y = mx + b 4 = 3(-2)+ b 4 = -6 + b +6 10 = b y = 3x + 10 substitute solve for b simplify

5. Practice 1)m = 3; b = 2 2)m = ½; b = 4 3) (5,10); m = 4 Write an equation for the given line that contains the given point and has the given slope. 4) (-3,8); m = 2 1.Y = 3x + 2 2.Y = ½x + 4 3.Y = 4x 10 4.Y = 2x + 14

6. Example 2 Write an equation for the line containing the points (1,5) and (2,8).

7. m = 3 y = mx + b y = 3x + b 5 = 3(1) + b 5 = 3 + b 3 =3 2 = b y = 3x + 2

8. Example 3 Write an equation for the line containing the points (1,5) and (2,8). y = mx + b 5 = 3(1)+ b 5 = 3 + b -3 2 = b y = 3x + 2 substitute simplify

9. Practice 1) (-4,1) (-1,4) Write an equation for the line that contains the given points. 2) (-3,5) (-1,-3)

10. Assignment Worksheet 8-5, 2-32 even (NO mixed review)