Multiple choice

If 𝛼 and 𝛽 are the roots of the quadratic equation π‘Žπ‘₯Β² + 𝑏π‘₯ + 8 = 0, where, π‘Ž,𝑏 ∈ 𝑅 and π‘Ž β‰  0, 𝛼 + 1 and 𝛽 + 1 are the roots of the quadratic equation π‘Žπ‘₯Β²οΉ£52π‘₯ + 𝑐 = 0 where 𝑐 ∈ R and, 𝛼﹣1 and 𝛽﹣1 are the roots of the quadratic equation π‘Žπ‘₯Β² + 8π‘₯ + 𝑑 = 0 where 𝑑 ∈ 𝑅, then find the value of 𝑐 + 𝑑.

  1. 54

  2. 53

  3. 42

  4. 46

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D Correct answer
Explanation

Using the sum of roots for the three quadratic equations, we get alpha + beta = -b/a, alpha + beta + 2 = 52/a, and alpha + beta - 2 = -8/a. Solving these equations gives a = 15 and b = -22. Using the product of roots, we find c = a - b + 8 = 45 and d = a + b + 8 = 1, which gives c + d = 46.

AI explanation

By Vieta's formulas, the sum of the roots of ax^2 + bx + 8 = 0 is alpha + beta = -b/a. For ax^2 - 52x + c = 0, the sum of the roots (alpha + 1) + (beta + 1) = 52/a, which means alpha + beta + 2 = 52/a. For ax^2 + 8x + d = 0, the sum of the roots (alpha - 1) + (beta - 1) = -8/a, meaning alpha + beta - 2 = -8/a. Solving these equations gives alpha + beta = 22/a, so c = 8 * 24/a and d = 8 * 20/a, leading to c + d = (192 + 160)/a = 46.