Calculating Travel Time and Writing Equations of Lines
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This guide provides a comprehensive overview for calculating total travel time on a road trip to California, including an example of current distances and travel hours. Additionally, it covers writing equations of lines in three forms: slope-intercept, point-slope, and standard form. Discover how to identify slope and intercepts, as well as example problems to guide you in finding equations from given points and slopes.
Calculating Travel Time and Writing Equations of Lines
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Presentation Transcript
Warm-up You are driving on a road trip and you want to find out how many hours total it will take you to get to California. After driving for 4 hours, you were 280 miles from home. You are now 520 miles from home and have driven for 8 hours. How long will it take you to drive 3000 miles?
3 Forms Slope-Intercept Point-Slope Standard **Always have the variables x & y**
Slope Intercept m is the slope of the line b is the y-intercept of the line
Example 1) Write the equation of the line that has a slope of 4, and a y-intercept of -2. 2) Write the equation of the line between the points (2, 4) and (4, 12).
Example 3) Write the equation of the line pictured.
Point-Slope (x1, y1) is a point on the line m is the slope of the line
Examples • Write the equation of the line that passes through the point (4, -2) and has a slope of 6. 5) Write the equation of the line that passes through the points (1, 8) and (-2, 6).
Standard Form Where A, B & C are integers A is NOT negative
Putting Equations into Standard Form 1) Put the equation into slope-intercept form. 2) Subtract mx from both sides (EX: y = 3x + 7 becomes –3x + y = 7) 3) If the number in front of x is negative, multiply everything by -1. 4) If the number in front of x is a fraction, multiply everything by the denominator.
Examples • Write the equation of the line that passes through the points (2, 6) and (3, -3) in standard form. • Write the equation of the line that has slope -5 and passes through the point (1, -4) in standard form. • Write the equation of the line through the points (3, -5) and (7, 1) in standard form.
Pop Quiz • You are given the slope of a line and a point on the line. How can you find an equation of the line? • You are given the slope of a line and the y-intercept of the line, how can you find an equation of the line? • You are given the x-intercept and the y-intercept of a line, how can you find an equation of the line?
WRITE THIS 1) Given slope (m) and y int (b): plug into y = mx + b 2) Given slope (m) and a point (x, y): plug into y = mx + b to find b. Then go to step 1. 3) Given two points (x1,y1) and (x2, y2): First find slope, then go to step 2.
Exit Ticket 9) Write the equation of the line perpendicular to the line y = ½ x + 8 through the point (1, -7) in all 3 forms.
Slope Intercept m is the slope of the line b is the y-intercept of the line
Example 1) Write the equation of the line that has a slope of 4, and a y-intercept of -2. 2) Write the equation of the line between the points (2, 4) and (4, 12).
Example 3) Write the equation of the line pictured.
Point-Slope (x1, y1) is a point on the line m is the slope of the line
Examples • Write the equation of the line that passes through the point (4, -2) and has a slope of 6. 5) Write the equation of the line that passes through the points (1, 8) and (-2, 6).
Standard Form Where A, B & C are integers A is NOT negative
Putting Equations into Standard Form 1) Put the equation into slope-intercept form. 2) Subtract mx from both sides (EX: y = 3x + 7 becomes –3x + y = 7) 3) If the number in front of x is negative, multiply everything by -1. 4) If the number in front of x is a fraction, multiply everything by the denominator.
Examples • Write the equation of the line that passes through the points (2, 6) and (3, -3) in standard form. • Write the equation of the line that has slope -5 and passes through the point (1, -4) in standard form. • Write the equation of the line through the points (3, -5) and (7, 1) in standard form.
Pop Quiz • You are given the slope of a line and a point on the line. How can you find an equation of the line? • You are given the slope of a line and the y-intercept of the line, how can you find an equation of the line? • You are given the x-intercept and the y-intercept of a line, how can you find an equation of the line?