Simplify: (23² − 16²) ÷ (23 − 16)

💡 Solution & Explanation

Use the identity a² − b² = (a + b)(a − b). So (23² − 16²) ÷ (23 − 16) = (23 + 16)(23 − 16) ÷ (23 − 16) = 23 + 16 = 39. This saves squaring 23 and 16: 529 − 256 = 273, and 273 ÷ 7 = 39 gives the same answer.