Evaluate [(2.39)² − (1.61)²] ÷ (2.39 − 1.61).

Problem restatement
Simplify a difference of squares divided by the corresponding difference.

Concept/Approach
Use a² − b² = (a − b)(a + b). Dividing by (a − b) leaves (a + b).

Step-by-Step calculation
[(2.39)² − (1.61)²] ÷ (2.39 − 1.61) = 2.39 + 1.61= 4.00

Verification/Alternative
Direct computation of squares is unnecessary once the identity is recognized.

Common pitfalls
Expanding both squares numerically instead of applying the identity.

Final Answer
4.00