9­4 (Factoring) H (taught).notebook
November 08, 2013
Bell Ringer
1.
9­4: Factoring to Solve Quadratic Equations
2.
SPI 3102.3.11 Analyze nonlinear graphs including quadratic functions that model a contextual situation.
3.
SPI 3102.3.10 Find the solution of a quadratic equation and/
or zeros of a quadratic function.
Nov 10­4:57 PM
Zero­Product Property For any real numbers a and b, if ab = 0, then a = 0 or b = 0.
Nov 10­4:48 PM
Example: Solve the quadratic equation.
a. (x + 1)(x ­ 5) = 0
b. (2x ­ 3)(x ­ 4) = 0
Ex. If (x + 3)(x + 2) = 0, then either x + 3 = 0 or x + 2 = 0.
Oct 16­11:40 AM
Your Turn: Solve the quadratic equation.
1. (2y + 1)(y + 14) = 0
2. (7n ­ 2)(5n ­ 4) = 0
Oct 16­11:42 AM
Steps to Solving by Factoring
1. Put in standard form and set equal to 0:
ax2 + bx + c = 0.
2. Look for GCF.
3. Factor into two binomials.
4. Set each binomial equal to 0 and solve. (Zero­Product Property)
Oct 16­11:44 AM
Nov 10­5:33 PM
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9­4 (Factoring) H (taught).notebook
Example: Solve by factoring: x2 ­ 24 = ­5x.
1. Put in standard form and set equal to 0:
ax2 + bx + c = 0.
November 08, 2013
Example: Solve by factoring.
a. x2 + 14x = ­49
b. 2a2 ­ 15a + 18 = 0
2. Look for GCF.
3. Factor into two binomials.
4. Set each binomial equal to 0 and solve. (Zero­Product Property)
Nov 10­5:35 PM
Your Turn: Solve by factoring.
1. m2 ­ 5m ­ 14 = 0
2. 3y2 ­ 17y + 22 = 0
Nov 10­5:39 PM
Example: The volume of a sandbox shaped like a rectangular prism is 48 ft3. The height of the sandbox is 2 feet. The width is w feet and the length is w + 2 feet. Use the formula V = lwh to find the value of w and the dimensions of the sandbox.
Nov 10­5:41 PM
Example: You are making a rectangular table. The area of the table should be 10 ft2. You want the length of the table to be 1 ft shorter than twice its width. What should the dimensions of the table be?
Oct 16­11:58 AM
Homework
pgs. 558­559 (#8­12 even, 14­28, 50)
Oct 16­11:53 AM
Oct 16­12:06 PM
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