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1.
Square of a number plus two times the number equal 63. What is the number ?
- A. 7
- B. 7
- C. 7
- D. 7
Answer: Option D
Explanation:
Let the number be x.
Then, x^2 + 2x = 63 [according to the question]
or, x^2 + 2x - 63 = 0
or, x^2 + 9x - 7x - 63 = 0
or, (x + 9) (x - 7) = 0
Therefore, x = 7 or - 9.
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