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Using the quadratic formula, the solutions of x² − 30x + 221 = 0 are:
A11 and 19
B13 and 17
C10 and 20
D9 and 21
Answer & Solution
Correct answer: B. 13 and 17
1. Discriminant: 30² − 4(221) = 900 − 884 = 16.
2. Square root of the discriminant: √16 = 4.
3. x = (30 ± 4)/2.
4. = 17 or 13.
5. So the solutions are 13 and 17 — verifying x² − 30x + 221 = (x − 13)(x − 17).
_Source: SCERT Kerala Std X Mathematics Part-2, Chapter 9-11 (pp 227-246, 2019 ed.)._
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