AlgebraMediumEquation from a geometric description
Algebra practice question
A rectangle's length is 4 times 1 less than its width w, and its length is also 8 more than twice its width. What is w?
Answer: 6
4(w − 1) = 2w + 8, so 4w − 4 = 2w + 8, 2w = 12, w = 6.
Common wrong answers
- If you answered 2
- 2 comes from 4w − 4 = 2w + 8 solved as 2w = 4, subtracting 4 from 8 instead of adding it.
- If you answered 12
- 12 is 2w, not w.
- If you answered 4.5
- 4.5 comes from 4w − 1 = 2w + 8 (forgetting to distribute the 4 to the −1).
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