Algebra practice question

Answer: A. 20

Doubling the first equation gives 6x + 4y = 24. For k = 24 the lines coincide; for any other k, such as 20, they are parallel and distinct: no solution.

Why the other answers are wrong

B. 24

k = 24 makes the equations identical — infinitely many solutions.

C. Any value of k gives a solution.

Every k except 24 gives no solution.

D. There is no such value of k.

Every value of k except 24 gives no solution, so such values exist.

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