Which of the following is the output of (141 x 141 x 141 - 58 x 58 x 58) /…

2025

Which of the following is the output of (141 x 141 x 141 - 58 x 58 x 58) / (141 x 141 + 141 x 58 + 58 x 58) ?

  1. A.

    67

  2. B.

    83

  3. C.

    98

  4. D.

    90

Attempted by 9 students.

Show answer & explanation

Correct answer: B

Step-by-Step Solution

To solve this efficiently without doing complex multiplication, we can use the algebraic identity for the difference of two cubes.

  1. Identify the structure: Let a = 141 and b = 58. The expression becomes: (a * a * a - b * b * b) / (a * a + a * b + b * b) Which is: (a^3 - b^3) / (a^2 + ab + b^2)

  2. Use the Algebraic Identity: Recall that a^3 - b^3 = (a - b) * (a^2 + ab + b^2).

  3. Simplify the expression: Substitute the identity into our fraction: [(a - b) * (a^2 + ab + b^2)] / (a^2 + ab + b^2)

    The term (a^2 + ab + b^2) cancels out from the numerator and the denominator, leaving us with: (a - b)

  4. Calculate the final value: a - b = 141 - 58 = 83.

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