Question 8
Algebraic ExpressionsFactorize 4x2 − 9y2 + 20x + 25
- A.(2x − 3y)(2x + 3y)
- B.(2x + 5)(2x − 9y + 5)
- C.(2x − 3y + 5)(2x − 3y − 5)
- D.(2x − 3y + 5)(2x + 3y + 5)
Show the answer and explanation
Answer: D ((2x − 3y + 5)(2x + 3y + 5))
Explanation
Group as (4x2 + 20x + 25) − 9y2 = (2x + 5)2 − (3y)2. As a difference of two squares this is (2x + 5 − 3y)(2x + 5 + 3y).