AlgebraEasy–MediumInequality from a perimeter limit
Algebra practice question
The side length of a square is x + 3 units. Which inequality represents all values of x for which the perimeter of the square is at most 40 units?
- A. x ≤ 7Correct
- B. x ≤ 10
- C. x < 7
- D. x ≥ 7
Answer: A. x ≤ 7
Perimeter = 4(x + 3) ≤ 40 → x + 3 ≤ 10 → x ≤ 7.
Why the other answers are wrong
- B. x ≤ 10
- x ≤ 10 forgets to subtract the 3.
- C. x < 7
- 'At most' allows equality, so ≤, not <.
- D. x ≥ 7
- The direction is reversed.
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