The area of a rectangular plot is 84 m2 and its length is 5 m more than its width. What is the width?
Answer and explanation
Correct answer: B. 7 m
- Step 1: Let the width be w, so w(w + 5) = 84. Step 2. w^2 + 5w - 84 = 0, which factorises as (w + 12)(w - 7) = 0. Step 3. w = 7 m, since a length cannot be negative. Answer: 7 m. Why not the others: 12 m: That is the length, not the width. 5 m: That is the difference between the length and width. 9 m: 9 x 14 = 126, not 84.
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