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