Algebra practice question

Answer: A. 5

Expand: 6x − 2x − 2c = 4x − 10, so 4x − 2c = 4x − 10. The x-terms match, so the equation holds for every x exactly when −2c = −10, i.e. c = 5.

Why the other answers are wrong

B. −5

c = −5 gives 4x + 10 = 4x − 10, which is never true (no solution).

C. 10

c = 10 gives 4x − 20 = 4x − 10, no solution.

D. There is no such value.

c = 5 makes both sides identical, so a value does exist.

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