Math Word Problems Demystified - A Self Teaching Guide

SOLUTION:

Step 1: Write in standard form

2 x^2 
 3 x
 5 ¼ 0

Step 2: Factor the left member

ð 2 x
 5 Þðxþ 1 Þ¼ 0

Step 3: Set both factors equal to zero

2 x
 5 ¼ 0 xþ 1 ¼ 0

Step 4: Solve each equation

2 x
 5 ¼ 0 xþ 1 ¼ 0

2 x
 5 þ 5 ¼ 0 þ 5 xþ 1 
 1 ¼ 0 
 1

2 x¼ 5 x¼
 1

21 x

21

¼

5

2

x¼

5

2

EXAMPLE:Solve 2x^2 ¼18.

SOLUTION:

Step 1: Write in standard form

2 x^2 
 18 ¼ 0

Step 2: Factor in the left member

2 ðx
 3 Þðxþ 3 Þ¼ 0

Step 3: Divide both sides by 2 and set both factors equal to zero

x
 3 ¼ 0 xþ 3 ¼ 0

228 REFRESHER VI Quadratic Equations