Advanced MathHardPerimeter from area and a relation
Advanced Math practice question
A rectangle's length is 3 units more than its width, and its area is 54 square units. What is its perimeter, in units?
Answer: 30
w(w + 3) = 54 gives (w + 9)(w − 6) = 0, so w = 6 and the length is 9. Perimeter: 2(6 + 9) = 30.
Common wrong answers
- If you answered 6
- 6 is the width alone.
- If you answered 9
- 9 is the length alone.
- If you answered 15
- 15 is width + length, half the perimeter.
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