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Warm Up. A chemist wants to create a 28% acid solution for an experiment by adding pure acid to a 20% acid solution. If he needs 20 liters of the mixture for his experiment, how many liters of each solution must he combine?. #1.
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Warm Up A chemist wants to create a 28% acid solution for an experiment by adding pure acid to a 20% acid solution. If he needs 20 liters of the mixture for his experiment, how many liters of each solution must he combine? #1 Jim says to Tina, “if you give me $18, then I’d have exactly five times as much money as you.” Tina replies, “Why that’s not fair. I think you should give me $6 then we’d have the same amount of money.” How much money does Jim have to start with? #2
Warm Up A chemist wants to create a 28% acid solution for an experiment by adding pure acid to a 20% acid solution. If he needs 20 liters of the mixture for his experiment, how many liters of each solution must he combine? #1 a= amount of 100% acid 0.28(20) = 5.6 b= amount of 20% acid solution 28% 100% 20% + = solution solution solution Amount of Solution a b 20 1.00a 5.6 0.20b acid
Warm Up A chemist wants to create a 28% acid solution for an experiment by adding pure acid to a 20% acid solution. If he needs 20 liters of the mixture for his experiment, how many liters of each solution must he combine? #1 a= amount of 100% acid b= amount of 20% acid solution
Warm Up Jim says to Tina, “if you give me $18, then I’d have exactly five times as much money as you.” Tina replies, “Why that’s not fair. I think you should give me $6, then we’d have the same amount of money.” How much money does Jim have to start with? #2 First exchange Second exchange Define variables: J = Jim’s money T = Tina’s money Write two equations E1 E2
Homework #3 If you decrease the denominator of a fraction by four, the new fraction that is equal to 1/2. If you subtract one from the numerator of the original fraction, then the resulting fraction would be 1/3. What is the product of the original numerator and denominator? Define variables: Write two equations n = Numerator E1 d = Denominator E2
Homework If you decrease the denominator of a fraction by four, the new fraction that is equal to 1/2. If you subtract one from the numerator of the original fraction, then the resulting fraction would be 1/3. What is the product of the original numerator and denominator? #3 Define variables: Write two equations n = Numerator E1 d = Denominator E2
Homework Five years ago, Beth was three times as old as Frank. Next year she will be twice as old as Frank. How old is Beth today? #6 Define variables: 5 years ago Next year B = Beth’s age F = Frank’s age Write two equations E1 E2
Homework #7 A rectangle has a perimeter of 18 inches. A new rectangle is formed by doubling the width and tripling the length. The new rectangle has a perimeter of 46 inches. Find the area of the new rectangle. Write two equations Define variables: E1 L = Length E2 W = Width
Homework #8 • A two-gallon mixture of fruit juice is comprised 15% orange juice. Michelle wants a fruit juice mixture to be 32% orange juice. How much pure orange juice should she add to the mixture? 0.15(2) = 0.3 a= amount of pure O.J. + b= amount of 32% O.J. = 32% 100% 15% solution solution solution Amount of Solution a 2 b 1.00a 0.3 0.32b O.J.
Homework #8 • A two-gallon mixture of fruit juice is comprised 15% orange juice. Michelle wants a fruit juice mixture to be 32% orange juice. How much pure orange juice should she add to the mixture? a= amount of 100% O.J. b= amount of 32% O.J.
Word Problems 5 4.8 21 23 126 120 0.5 6
Homework Sadie works at the China Emporium packing dishes for shipments. She receives 12 cents for each piece she packs successfully and is fined 18 cents for each piece she breaks. If she handles 188 pieces and is paid $20.16, how many pieces does she break? #1 Write two equations Define variables: E1 p = number packed b = number broken E2
Homework Traveling against the wind, a plane flies 2,100 miles from Chicago to San Diego in 4 hours and 40 minutes. The return trip, flying with a wind that is blowing twice as fast, takes four hours. Find the rate of the plane in still air. #2 w = speed of wind (to S.D.) p = speed of the plane To S.D. Against the wind To Chicago With the wind
Homework Traveling against the wind, a plane flies 2,100 miles from Chicago to San Diego in 4 hours and 40 minutes. The return trip, flying with a wind that is blowing twice as fast, takes four hours. Find the rate of the plane in still air. #2 w = speed of wind (to S.D.) p = speed of the plane
Homework One number is two-thirds of another number. If the larger number is increased by 9 it becomes twice as large as the smaller number. Find the product of the two numbers. #3 Define variables: L = Larger number S = Smaller number Write two equations E1 E2
Homework A store received $823 from the sale of 5 iPods and 7 video games. The receipts from the iPods exceeded receipts from the video games by $137. What is the cost of a video game? #4 Write two equations Define variables: p = cost of an iPod E1 v = cost of a video game E2