Equations of Lines

Equations of Lines: From Algebra 1, you may recall the following equations/formulas: Slope Formula: Slope-Intercept Equation: Point-Slope Equation:

An equation in slope-intercept form of the line with slope of 6 and y-intercept of –3 is given by: -3

Write an equation in slope-intercept form of the line with slope of –1 and y-intercept of 4. B C D x + y = 4 y = x – 4 y = –x – 4 y = –x + 4 Lesson 3-4 CYP 1

Write an equation in point-slope form of the line whose slope is passing through the point (-10, 8) 8 -10

Write an equation in point-slope form of the line whose slope is that contains (6, –3). A B C D Lesson 3-4 CYP 2

0 – 9 -2 – 4 9 4 Step 1: Find the slope using the formula: Write an equation in slope-intercept form for a line containing (4, 9) and (–2, 0). Step 1: Find the slope using the formula: 0 – 9 -2 – 4 Step 2: Substitute into point-slope equation: 9 4

Step 3: Simplify to slope-intercept equation: +9 +9

Write an equation in slope-intercept form for a line containing (3, 2) and (6, 8). B C D Lesson 3-4 CYP 3

Recall that parallel lines have equal slope values. Perpendicular lines have slopes that are negative reciprocals of each other .

Use three-step process using slope (m) = 2 and point values provided. Write an equation in slope-intercept form for a line containing (1, 7) that is perpendicular to the line Use three-step process using slope (m) = 2 and point values provided.

Write an equation in slope-intercept form for a line containing (–3, 4) that is perpendicular to the line A B C D Lesson 3-4 CYP 4

Use the slope formula by using A (-1, 6)and B (3, 2) or any other pair of points with integer coordinates. Since y-intercept is 5, the equation is:

Rise = -6 Slope (m) = -1 Run = 6 y-intercept (b) = 5 Equation: y = -x + 5