Bellwork Find the slope of the line containing the points (-1,12) and (5,-6). Find the product of the slope and y-intercept for the line y=-5x+7. Write the equation in slope-intercept form for the line that has a y-intercept of 0 and a slope of -1. Does the table below represent a linear relationship? x 2 3 4 5 6 y -24 -18 -14 -4 -2
Lesson 1.3 Linear Equations in two variables Algebra 2 Lesson 1.3 Linear Equations in two variables
Objectives: Write a linear equation in two variables given sufficient information.
Key concept: Write an equation in slope-intercept form for the line containing the points (4,-3) and (2,1). 1st: find the slope m = 1 – (-3) = 4 = -2 2-4 -2 m= -2 2nd: find the y-intercept y=mx + b 1 = -2(2) + b 1 = -4 + b 5 = b 3rd: Write the equation y=-2x +5
Try These: Answer: y = -x - 2 DIRECTIONS: Write an equation in slope intercept form for the line that has the given points. 1.) (1,-3) and (3,-5) Answer: y = -x - 2 2.) (8,-3) and (-8,3) Answer:
Key concept: Point-slope form y-y₁= m(x-x₁) EXAMPLE: Write an equation in slope intercept form for the line that has a slope of ½ and contains the point (-8,3). y – 3 = ½(x- -8) y – 3 = ½x + 4 y = ½x + 7
Try These: Answer: y = -⅔x - 1 DIRECTIONS: Write an equation in slope intercept form for the line that has the given slope and contains the given point. 1.) slope = -⅔ and point (6,-5) Answer: y = -⅔x - 1 2.) m=0, (-7,8) Answer: y = 8
Homework Lesson 1.3 Page 26 (10-30 EVENS)