AlgebraEasy–MediumSystem solved by substitution with a difference
Algebra practice question
If x − y = 1 and x + 2y = 10, what is the value of x?
Answer: 4
x = y + 1, so y + 1 + 2y = 10 gives y = 3 and x = 4.
Common wrong answers
- If you answered 3
- 3 is y.
- If you answered 5
- 5 halves 10.
- If you answered 7
- 7 is x + y.
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