Multiple choice

One of the roots of x2 - 20x + k = 0, is 9. Quantity A k Quantity B 100

  1. Quantity A is greater.

  2. Quantity B is greater.

  3. The two quantities are equal.

  4. The relationship cannot be determined from the information given.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

If 9 is a root, 9^2 - 20(9) + k = 0. 81 - 180 + k = 0, so k = 99. Quantity A is 99, Quantity B is 100. Quantity B is greater.

AI explanation

Substitute the known root x = 9 into the quadratic equation x^2 - 20x + k = 0 to get 81 - 180 + k = 0. Solving this gives k = 99. Since Quantity B is 100, Quantity B is greater.

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