Question 7
Quadratic EquationsWhich of the following is a perfect square?
- A.x2 − 3x − 4
- B.x2 + 9x + 9
- C.2x2 + 2x + 2
- D.x2 + 2x + 1
Show the answer and explanation
Answer: D (x2 + 2x + 1)
Explanation
x² + 2x + 1 = (x + 1)²; none of the others factorise as a square.