Advanced MathMediumConstant in a factored difference of squares
Advanced Math practice question
For all values of x, 3x² − 12 = 3(x − a)(x + a), where a is a positive constant. What is the value of a?
Answer: 2
3x² − 12 = 3(x² − 4) = 3(x − 2)(x + 2).
Common wrong answers
- If you answered 4
- 4 is a², not a.
- If you answered 6
- 6 halves 12 instead of dividing by 3 and taking a root.
- If you answered 12
- 12 is the constant before factoring out 3.
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