Advanced MathMediumPerimeter of a square from its area as a trinomial
Advanced Math practice question
The area of a square is 9x² + 30x + 25 square units, where x > 0. Which expression gives the perimeter of the square?
- A. 12x + 20Correct
- B. 3x + 5
- C. 6x + 10
- D. 36x² + 120x + 100
Answer: A. 12x + 20
9x² + 30x + 25 = (3x + 5)², so each side is 3x + 5 and the perimeter is 4(3x + 5) = 12x + 20.
Why the other answers are wrong
- B. 3x + 5
- 3x + 5 is one side, not the perimeter.
- C. 6x + 10
- 6x + 10 is two sides.
- D. 36x² + 120x + 100
- That is four times the area, not the perimeter.
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