Advanced MathEasy–MediumConstant from a conjugate product
Advanced Math practice question
When (x + 7)(x − 7) is written as x² − k, what is the value of k?
Answer: 49
(x + 7)(x − 7) = x² − 49.
Common wrong answers
- If you answered 7
- 7 copies the number in the factors.
- If you answered 14
- 14 adds 7 and 7.
- If you answered -49
- −49 has the sign wrong for k.
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