Solve: The length of a rectangular picture frame is 4 inches less than its width. The area of the picture frame is 320 square inches. Find the dimensions of the picture frame. Review: 6.5i Mini-Quiz

Class Greeting

Objective: Students will solve real world problems involving quadratic equations. (continued)

Solving real world word problems involving Quadratic Equations (continued) Chapter 6 – Factoring and Solving Equations Section 5j

Example Find the number of video games needed to be sold to have a profit of $30 by solving the equation by factorization. 30 = -0.4x 2 + 8x – x 2 – 8x + 40 = 0 4x 2 – 80x = 0 x 2 – 20x = 0 (x – 10) 2 = 0 x = {10} Answer: 10 video games need to be sold for a profit of $30. x 2 – 20x = 0 0.4x 2 – 8x + 10 = -30 Switch sides and change all the signs. Add 30 to both sides. Switch sides and change all the signs. Add 30 to both sides. Multiply everything by 10. Switch sides and change all the signs. Add 30 to both sides. Multiply everything by 10. Divide everything by 4. P = ? Standard Form: Ax 2 + Bx + C = 0

Preview 370/67 e. Find the number of video games needed to be sold to have a profit of $20 by solving the quadratic equation. a. Find the standard form of the equation. Ax 2 + Bx + C = 0 d. Find the x-intercepts of the graph. b. Make an (x, y) table. c. Graph the ordered pairs (x, y).

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Example

Preview 371/69c Example 2 [ ] ] 2 [ must be positive

Homework /67 and 69

Lesson Summary: Objective: Students will solve real world problems involving quadratic equations. (continued)

Preview of the next Lesson: Objective: The students will correct their practice test on sections 6-4 and 6-5.