AlgebraEasy–MediumNumber giving equal results under two rules
Algebra practice question
When a number is multiplied by 6 and then decreased by 9, the result is the same as when the number is multiplied by 3 and then increased by 6. What is the number?
Answer: 5
6n − 9 = 3n + 6 gives 3n = 15, so n = 5.
Common wrong answers
- If you answered 3
- 3 comes from 9n = 15 with rounding.
- If you answered 15
- 15 is 3n, not n.
- If you answered -1
- −1 comes from 6n − 9 = 3n − 6, a sign slip.
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