SWBAT… Write lines in slope-intercept form Mon, 11/28 Agenda 1.WU (10 min) 2.Slope quiz review (5 min) 3.5 Practice problems - slope-intercept form (20 min) Warm-Up 1. Find the slope of (6c, 2d) and (8c, 4d) 2. The table shows production costs for building different numbers of skateboards. Determine the missing value, x, that will result in a linear model. HW4: Writing Equations in slope-intercept form Skateboards BuiltProduction Costs ($) x

When an equation is in slope-intercept form: What is the slope? ____________ Now look at the equation below…… What is the y-intercept? ____________

Given y = ½x + ¾, what is the slope and the y-intercept? m = ½ b = ¾

Given y = ½x – ¾, what is the slope and the y-intercept? m = ½ b = -¾

Given y = -½x – ¾, what is the slope and the y-intercept? m = -½ b = -¾

y = mx+ b is an equation that defines a line A line has two characteristics Slope Points that fall on the line (the y-intercept is on the line)

Converting linear equations into Slope-Intercept Form, y = mx + b Our main goal is to get the y alone on one side of the equation 6 Examples

Example 1 - convert into Slope-Intercept Form (divide both sides by 2 to get y alone) (now simplify all fractions) 21 What is the slope? _____What is the y-intercept? ______

Example 2 – Convert to Slope-Intercept Form -3y = -9x – 12 Step 1: Divide both sides by -3 to get y alone Step 2: Simplify all fractions Step 3: Write your equation in y = mx + b What is the slope? ____________ What is the y-intercept? ____________

*** Check Your Answer *** -3y = -9x – 12 (divide both sides by -3 to get y alone) (now simplify all fractions) y = 3x y = -9x – Slope = 3 Intercept = 4 Wow, you’re good at this!!

Example 3: Convert to Slope-Intercept Form 21x – 7y =14 (subtract both sides by 21x) -7y = -21x + 14 (now divide both sides by -7) y = 3x – 2 (simplify all fractions) What is the slope? _________ What is the y-intercept? ________

2y + 26 = -6x Step 1: Subtract both sides by 26 Step 2: Divide both sides by 2 to get y by itself Step 3: Simplify all fractions Example 4: Convert to Slope-Intercept Form What is the slope? ____________ What is the y-intercept? ____________

2y + 26 = -6x (subtract both sides by 26) 2y = -6x – 26 (now divide both sides by 2 y = -3x – 13 (simplify all fractions) You are a math wizard! *** Check Your Answer ***

Example 5: In the standard (x, y) coordinate plane, what is the slope of the line given by the equation 5x – 4y = 3?

Example 6: In the standard (x, y) coordinate plane, what is the slope of the line given by the equation 4y = 24?

What is the slope of 5x + 4y = 80 A. m = -5 x 4 B. m = -5 C. m = -4 D. m = /3

Which equation(s) has the same y-intercept as y = ½x + 2? A. y = 2x + 4 B. 2 – y = ½x C. y – 2 = x D. y = x 2/3

Which equation is parallel to the line -2x + 4y = 3? A. y = -1/2 x + 5 B. y = 2x – 6 C. y = -2x + 4 D. y = ½x – 2 3/3

Video: Families of Linear Graphs student/mathematics/assets/animati on/algebra1/ALG1CIM4-3.swf