Advanced MathEasy–MediumPositive root of a quadratic in a simple frame
Advanced Math practice question
The square of a positive number, minus the number, is 30. What is the number?
Answer: 6
n² − n − 30 = (n − 6)(n + 5) = 0, so n = 6 (positive).
Common wrong answers
- If you answered 5
- 5 gives 25 − 5 = 20.
- If you answered 30
- 30 gives 900 − 30 = 870.
- If you answered -5
- −5 is the rejected negative root.
More Advanced Math questions
- Easy–Medium
If f(x) = 2x² − 3, what is f(4)? - Easy–Medium
Which expression is equivalent to (2x³)(3x⁴)? - Easy–Medium
What are the solutions to x² − 16 = 0? - Easy–Medium
Which expression is equivalent to (x + 5)²? - Easy–Medium
For x ≠ 0, which expression is equivalent to (x² + 3x) / x? - Easy–Medium
What are the solutions to the equation 2(x − 3)² − 32 = 0 ?
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