Name _______________________________________________ Date ________ Lesson 4.2 – Writing Equations of Lines CC Geometry Do Now Write the equation of the line, given the slope and y-intercept.

a) m = 6 b) m = -3 c) m = 41 d) m = -

32 e) m = 1

b= 2 b = -7 b = 1 b = 0 b = -10 Slope-Intercept form of a line: y = mx + b, m = slope and b = y-intercept Slope Formula: 𝑚 = 𝑦2−𝑦1

𝑥2−𝑥1

1. Write the equation of a line that passes through the point (-5, 2) and has a slope of 5. 2. Write the equation of a line that passes through the point (3, -2) and has a slope of -3. 3. Write the equation of the line which passes through the points (6, 2) and (4, 3). 4. Write the equation of the line which passes through the points (-2, 0) and (-4, 1).

Answer key

Point-Slope form of a line: 𝑦 − 𝑦1 = 𝑚(𝑥 − 𝑥1), m = slope and (𝑥1, 𝑦1) is any point on the line. 5. Determine the point and slope for the following examples: a) y – 5 = 6(x – 8) b) y + 2 = 3(x + 4) c) y – 7 = -4(x + 5) d) y = 3(x – 2) – 4 6. Write the equation of a line that passes through the point (2, 5) and has a slope of 2. 7. Write the equation of a line that passes through the point (3, -8) and has a slope of -9.

8. Write the equation of a line given the points (-3, 5) and (3, 11). 9. Write the equation of a line given the points (4, 9) and (6, 5).

Point = m =

Point = m =

Point = m =

Point = m =

Graph the following using point slope form of a line: 10. )4(8 �� � xy 11. )2(45 � � xy

12. )1(29 �� � xy 13. 5)2(3 �� xy

14. Write the equation of a line that passes through the points (1, -4) and (3, 2). 15. Write the equation of a line that passes through the points (4, -7) and (0, 5). 16. Find the slope of a line that passes through the points (-1, -5) and (3, 7).