Algebra 1 Notes Lesson 5 3 SlopeIntercept Form

Algebra 1 Notes Lesson 5 -3: Slope-Intercept Form

Objectives • Write and graph linear equations in slope intercept form • Model real world situations with an equation in slope intercept form

Slope-Intercept Form The linear equation y = mx + b is written in slope-intercept form, where m is the slope and b is the y-intercept.

Slope-Intercept Form The linear equation y = mx + b It is VERY easy to graph lines in this form.

Example 1 Write an equation of the line whose slope is ¼ and whose y-intercept is -6. y = mx + b y = ¼x + (-6) y = ¼x – 6

Example 1 Write an equation of the line whose slope is -5 and whose y-intercept is 16. y = mx + b

Example 1 Write an equation of the line whose slope is -5 and whose y-intercept is 16. y = mx + b y = -5 x + 16

Example 2 Write an equation of the line shown in the graph. slope: y-intercept:

Example 2 Write an equation of the line shown in the graph. slope: y-intercept: 3 or

Example 3 Graph y-intercept:

Example 3 Graph y-intercept: -7 Graph (0, -7). Slope: From (0, -7), move up 1 unit and right 2 units. Draw a point. Draw a line connecting the points.

Example 4 Graph 5 x + 4 y = 8

Example 4 Graph 5 x + 4 y = 8 -5 x

Example 4 Graph 5 x + 4 y = 8 -5 x 4 y = -5 x + 8

Example 4 Graph 5 x + 4 y = 8 -5 x 4 y = -5 x + 8 4 4 y-intercept:

Example 4 Graph 5 x + 4 y = 8 -5 x 4 y = -5 x + 8 4 4 y-intercept: 2 Slope:

Write equation given 2 points (0, 3) & (2, -1)

Write equation given 2 points (0, 3) & (2, -1) M = -2

Write equation given 2 points (0, 3) & (2, -1) M = -2 b=3

Write equation given 2 points (0, 3) & (2, -1) M = -2 b=3 y = -2 x + 3

Write equation given 2 points (4, 6) & (0, -5)

Write equation given 2 points (4, 6) & (0, -5) m=

Write equation given 2 points (4, 6) & (0, -5) m= b = -5

Write equation given 2 points (4, 6) & (0, -5) m= b = -5 y= x-5

End Day One

Begin Day Two • Pass out 5 -3 story problem worksheet

The average heart rate for a twenty-five year old while exercising is 117 beats per minute. The rate drops 3 beats for every 5 years older. 1) Write an equation to represent this is slope intercept form. Variables x= y=

The average heart rate for a twenty-five year old while exercising is 117 beats per minute. The rate drops 3 beats for every 5 years older. 1) Write an equation to represent this is slope intercept form. Variables x= Years after 25 y= Beats per Minute

The average heart rate for a twenty-five year old while exercising is 117 beats per minute. The rate drops 3 beats for every 5 years older. 1) Write an equation to represent this is slope intercept form. Variables Information x= Years after 25 m= y= Beats per Minute b=

The average heart rate for a twenty-five year old while exercising is 117 beats per minute. The rate drops 3 beats for every 5 years older. 1)Write an equation to represent this is slope intercept form. Variables Information x= Years after 25 m= -⅗ y= Beats per Minute b=

The average heart rate for a twenty-five year old while exercising is 117 beats per minute. The rate drops 3 beats for every 5 years older. 1)Write an equation to represent this is slope intercept form. Variables Information x= Years after 25 m= -⅗ y= Beats per Minute b= 117

The average heart rate for a twenty-five year old while exercising is 117 beats per minute. The rate drops 3 beats for every 5 years older. 1)Write an equation to represent this is slope intercept form. Variables Information Equation x= Years after 25 m= -⅗ y= Beats per Minute b= 117

The average heart rate for a twenty-five year old while exercising is 117 beats per minute. The rate drops 3 beats for every 5 years older. 1)Write an equation to represent this is slope intercept form. Variables Information Equation x= Years after 25 m= -⅗ y=-⅗x +117 y= Beats per Minute b= 117

2) Graph the situation.

Find the average heart rate for a person who is 55 years old. y = mx + b

Find the average heart rate for a person who is 55 years old. y = mx + b y = -⅗(30) + 117

Find the average heart rate for a person who is 55 years old. y = mx + b y = -⅗(30) + 117 y = 99

Find the average heart rate for a person who is 55 years old. y = mx + b y = -⅗(30) + 117 y = 99 99 beats per minute

Classwork Pgs. 275 -276: 14 -44 Evens, 47 -49 All

Homework: Worksheet