Simplify: (a + b)² − (a − b)²
Show answer & explanation
Correct answer: D
Explanation
(a + b)² − (a − b)²
According to the formula:
(a + b)² = a² + 2ab + b²
(a − b)² = a² − 2ab + b²
(a² + 2ab + b²) − (a² − 2ab + b²)
= a² + 2ab + b² − a² + 2ab − b²= 4ab