2. CHAPTER 9 Quadratic Equations Slide 2Copyright 2011, 2007, 2003, 1999 Pearson Education, Inc. 9.1Introduction to Quadratic Equations 9.2Solving Quadratic Equations by Completing the Square 9.3The Quadratic Formula 9.4Formulas 9.5Applications and Problem Solving 9.6Graphs of Quadratic Equations 9.7Functions

3. OBJECTIVES 9.4 Formulas Slide 3Copyright 2011, 2007, 2003, 1999 Pearson Education, Inc. aSolve a formula for a specified letter.

4. Solving Formulas Formulas can be linear, rational, radical, or quadratic equations, as well as other types of equations. To solve formulas, we use the same steps that we use to solve equations. Probably the greatest difference is that while the solution of an equation is a number, the solution of a formula is generally a variable expression. 9.4 Formulas a Solve a formula for a specified letter. Slide 4Copyright 2011, 2007, 2003, 1999 Pearson Education, Inc.

5. EXAMPLE Solution y = bw – cw + 3 We want the w alone on one side. y – 3 = bw – cw Subtracting 3 y – 3 = w(b – c) Collecting like terms Dividing by b – c on both sides 9.4 Formulas a Solve a formula for a specified letter. ASolve for w: y = bw – cw + 3. Slide 5Copyright 2011, 2007, 2003, 1999 Pearson Education, Inc.

6. EXAMPLE Solution Multiply each side by the LCD Factor out the GCF 9.4 Formulas a Solve a formula for a specified letter. BSolve: Slide 6Copyright 2011, 2007, 2003, 1999 Pearson Education, Inc.

7. EXAMPLE Solution Square both sides Solve for y. 9.4 Formulas a Solve a formula for a specified letter. CSolve: Slide 7Copyright 2011, 2007, 2003, 1999 Pearson Education, Inc.