1. Warm-Up Dave bought 7 tacos and 3 burritos for $36. For the same price he could have bought 2 tacos and 6 burritos. How much do both tacos and burritos cost? T = $3 B =$5 Let T – Cost of Tacos B – Cost of Burritos

2. Objective: (1) Students will solve word problems using systems of equations. CA Standards 9.0: Students solve a system of two linear equations in two variables algebraically and are able to interpret the answer graphically. Students are able to solve a system of two linear inequalities in two variables and to sketch the solution sets. Agenda: 12/06/2011 1.) Warm-up 2.) Lesson: Word Problems – Cost Quantity (ppt.) 3.) Class/Home Work One (1) Assignment 4.) STAY ON TASK!!!!

3. 8.4 Word Problems – Cost/Quantity Notes: Word Problems Type: Cost Quantity Ex 1) A local record company sells CDs for $15 and DVDs for $20. If they made $170 while selling 10 items, how many of each did they sell? 15C + 20D = 170 C + D = 10 5 5 D = 4 C + D = 10 C + (4) = 10 -4 Let C – # of CDs D – # of DVDs 0 5D = 20 -15-15C –15D = -150 15C + 20D = 170 C = 6 +

4. 10C + 18D = 188 8.4 Word Problems – Cost/Quantity Try this one: Ex 2) A local record company sells CDs for $10 and DVDs for $18. If they made $188 while selling 14 items, how many of each did they sell? 10C + 18D = 188 C + D = 14 8 8 D = 6 C + D = 14 C + (6) = 14 -6 Let C – # of CDs D – # of DVDs 0 8D = 48 -10-10C –10D = -140 C = 8 +

5. 5B + 3T = 36 8.4 Word Problems – Cost/Quantity Notes: Word Problems Type: Cost Quantity Ex 3) Burritos cost $5 and tacos cost $3. How many of each did I buy if I got 8 items for $36? 5B + 3T = 36 B + T = 8 -2 T = 2 B + T = 8 B + (2) = 8 -2 Let B – # of Burritos T – # of Tacos 0 – 2T = -4 -5 -5B – 5T = -40 B = 6

6. B = 16 3B + 1T = 53 8.4 Word Problems – Cost/Quantity Try this one !!!!! Ex 4) Burritos cost $3 and tacos cost $1. How many of each did I buy if I got 21 items for $53? 3B + 1T = 53 B + T = 21 -2 T = 5 B + T = 21 B + (5) = 21 -5 Let B – # of Burritos T – # of Tacos 0 – 2T = -10 -3 -3B – 3T = -63

7. 8C + 12A = 48 8.4 Word Problems – Cost/Quantity Notes: Word Problems Type: Cost Quantity Ex 5) A child’s ticket costs $8 for admission into the movie theater. Adult tickets cost $12. How many of each did a family get if they spent $48 for 5 tickets? 8C + 12A = 48 C + A = 5 4 4 A = 2 C + A = 5 C + (2) = 5 -2 Let C – # of Child tickets A – # of Adult tickets 0 4A = 8= 8 -8 -8C – 8A = -40 C = 3 +