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Forms of a Line. The Murchison Middle School NJHS is selling t-shirts and caps to raise money for their DC trip. They earn a profit of $5 per shirt and $10 per cap. Find 5 pairs of numbers for shirt and cap sales that will allow the students to make exactly $600 profit.
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The Murchison Middle School NJHS is selling t-shirts and caps to raise money for their DC trip. They earn a profit of $5 per shirt and $10 per cap. • Find 5 pairs of numbers for shirt and cap sales that will allow the students to make exactly $600 profit.
The Murchison Middle School NJHS is selling t-shirts and caps to raise money for their DC trip. They earn a profit of $5 per shirt and $10 per cap. • The values you found can be expressed as an ordered pair (s, c). Plot these ordered pairs on a grid, with shirts as x and caps as y.
The Murchison Middle School NJHS is selling t-shirts and caps to raise money for their DC trip. They earn a profit of $5 per shirt and $10 per cap. • Write the equation of the line on your graph in slope intercept form, y=mx+b. • What do “m” and “b” mean in this problem?
The Murchison Middle School NJHS is selling t-shirts and caps to raise money for their DC trip. They earn a profit of $5 per shirt and $10 per cap. • Write the equation of the line on your graph in point-slope form, y-y1 = m(x-x1). • What do “m” and “(x1, y1)” mean in this problem?
The Murchison Middle School NJHS is selling t-shirts and caps to raise money for their DC trip. They earn a profit of $5 per shirt and $10 per cap. • A more meaningful equation for this problem would be: 5s + 10c = 600. • What do the 5, 10, and 600 mean in this problem situation? • How can you use this to find other solutions?
Notes • Standard Form: Ax + By = C • Rule 1: A is always positive • Rule 2: A, B, and C are always whole numbers. • A, B, and C are not anything “algebraic” but are important information in the problem. • Standard form does not show • slope • intercepts • points
Try a similar example… • Students are selling calendars for $3 each and posters for $2 each. They want to sell a total of $100 worth of products. • Write an equation using p, for posters, and c for calendars. • Use your equation to answer the question: How many posters must they sell if they have already sold 20 calendars?
Try a similar example… • Eric walks 80 meters per minute and runs 200 meters per minute. He wants to cover a distance of 1600 meters by both walking and running. If he walks for 10 minutes, how many minutes must he run? • Write the equation first. What info is NOT needed for the equation? • Answer the question. Where do you find the info needed to answer the question?
Other types of Standard Form Problems • Two rates, find totals • Two totals, find rates • Money • Perimeter • Totals • Ratios
Try a TWO TOTALS example… • Courtney bought 7 bags of chips and 12 packages of hot dogs. She spent $27. How much were the chips if the hot dog packages were $0.50? • Write the equation. • Answer the question.
Try a MONEY example… • Neema saves quarters and dimes. She has a total of $1.65. How many dimes does she have if she has 5 quarters? • Write the equation. • Answer the question.
Try a PERIMETER example… • A pool has a perimeter of 500 meters. What is the length if the width is 100 meters? • Write the equation. • Answer the question.
Try a TOTALS example… • Luanne recycles cans and bottles. She has a total of 225 recyclables. How many cans does she have if she has 127 bottles? • Write the equation. • Answer the question.
Try a RATIO example… • The ratio of desks to tables in the building is 2 to 15. How many tables are there if there are 34 desks? • Write the equation. • Answer the question.