AlgebraMediumSmallest positive integer solution of a two-variable equation
Algebra practice question
In the equation 3x − 2y = 7, both x and y are positive integers. What is the smallest possible value of x?
Answer: 3
x = 1 gives y = −2 and x = 2 gives y = −1/2, neither allowed; x = 3 gives y = 1.
Common wrong answers
- If you answered 1
- 1 gives y = −2, which is not positive.
- If you answered 2
- 2 gives y = −1/2, not an integer.
- If you answered 7
- 7 solves 3x = 7 + 2y with y = 7, but smaller x work.
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