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Would you rather …?. Work a job for a month for 1 penny the first day and double it each day for a month? Or… Work a job for a month and make $5,000,000 at the end of the month? Justify your choice. Starter Goal: Complete in 7 minutes.
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Would you rather …? • Work a job for a month for 1 penny the first day and double it each day for a month? • Or… • Work a job for a month and make $5,000,000 at the end of the month? • Justify your choice.
Starter Goal: Complete in 7 minutes • Find the slope of the line containing (-2,8) and (-4,-3). • What is the slope and the y-intercept? • y = -4/5x - 8 • Graph • y = 2/3x - 4
Lesson 6F.IF.4 Algebra 1 Standard Form
STANDARD FORM: Ax + By = C • no fractions/decimals • A must be positive Example:2x – 4y= -7 where A = 2, B = -4, C = -7 To graph from standard form, convert to slope-intercept form (y = mx + b)
Or…Use shortcuts! (if you memorize them) Shortcuts:☻ Ax + By = C -Ax -Ax By = -Ax + C B B y = -A x + C BB Slope(m) = -A y-intercept(b) = C B B m = -2 or 1 b = -7 or 7 -4 2 -4 4
STANDARD FORM: Ax + By = C • no fractions/decimals • A must be positive Example:2x – 4y = -7 where A = 2, B = -4, C = -7 To graph from standard form, convert to slope-intercept form (y = mx + b) OR…
Starter • Grab a white board and marker OR a piece of graph paper from bookshelf! • Graph 3x – 6y = 12 • Is it a function? • What is the domain? ( , ) • What is the range?( , ) • What is the equation in slope-intercept form? • Do you have test corrections to turn in? Hmm? Hmm?
Write in standard form Ax + By = C 1) y = -2/5x + 1 2) y = 4 – 5x
Write in standard form. Ax + By = C 3) y = 2/3x – 1/7 4) y = -4/5x + 2/3
Graph 5) y = -3 6) x = 6
7) Jackie is selling tickets for the school concert: $2 for students and $4 for adults. She hopes to sell $600 worth of tickets. Write an equation to model this situation, then graph it.
8) You are in charge of buying hamburgers and chicken for a barbecue. The hamburger cost $2 per pound and chicken cost $3 per pound. You have $30 to spend. Write and graph an equation to model this situation.
Notes Parallel lines are two lines that never intersect. They have the same slope. ----------------------------------------------------------- Perpendicular lines are two lines that intersect to form right angles. They have opposite reciprocal slopes. (example: m = 2/3 and m = -3/2)
Examples a) y = -2/3x + 7 b) y = -3/2x + 4 c) y = 2/3x – 4 d) y = -2/3x – 2 5) Which lines are parallel? 6) Which lines are perpendicular?
Your Turn! • HW: worksheet “Why Did the Cow Want a Divorce? / Why Does a Poor Man Drink Coffee?” • Use shortcuts or use slope-intercept form!
You can also graph by finding the x-intercept and y-intercept (b). • 4x – 9y = 12 2) 5x + 3y = 15 x-int: (__, 0) x-int: (__, 0) y-int: (0, __) y-int: (0, __)