1. Lesson 5-8: Problem Solving
Objective:
Students will complete word problems by factoring then solving

2. Steps
►Define Variables
► Translate the equation
►Solve by factoring (set = 0)
► Write sentence

3. Ex 1: The square of a number minus the number is 20. Find the number.
Number: n
n2 –n=20
n2 –n-20=0
(n-5)(n+4) =0
n=5 or n=-4

4. The length can not be negative so the only solution is 8 cm
Example 2:
The width of a rectangle is 5 cm less than
the length. The area is 24 cm2. Find the
dimensions.
length: x
width: x – 5
x(x-5) = 24
x2 -5x - 24 =0
(x - 8)(x + 3)=0
x = 8 or x = -3
4) The length is 8cm and the width is 3 cm
A = bh
The length can not be negative so the only solution is 8 cm

5. Ex 3:
The sum of the squares of 2 consecutive odd positive integers is Find the integers.
x2 + (x+2)2 = 394
x2 + x2 + 4x +4 = 394
2x2 + 4x – 390=0
2(x2 +2x – 195)=0
2(x -13)(x+15) = 0
x=13 or x =-15
1st: x
2nd: x +2

6. Marker Board pg 235 2 6 12 16

7. Assignment
5-8/ /1-15o, 24-30