16Hit1600
AlgebraVery hardValue of a constant giving no solution

Algebra practice question

In the equation 4(x + k) = 4x + 12 − 2k, k is a constant. For which value of k does the equation have NO solution?

  1. A. No such value exists; the equation has infinitely many solutions for k = 2 and no solution for every other k.Correct
  2. B. k = 2
  3. C. k = 3
  4. D. k = 0

Answer: A. No such value exists; the equation has infinitely many solutions for k = 2 and no solution for every other k.

Expand: 4x + 4k = 4x + 12 − 2k. The x-terms cancel, leaving 4k = 12 − 2k, i.e. 6k = 12. If k = 2 this is 0 = 0 (infinitely many solutions); for any other k it is a false statement (no solution). So no single k gives 'no solution' — every k except 2 does.

Why the other answers are wrong

B. k = 2
k = 2 gives 0 = 0: infinitely many solutions, not none.
C. k = 3
k = 3 gives no solution, but so does every k except 2; it is not THE value.
D. k = 0
k = 0 likewise gives no solution, as does any k ≠ 2.

More Algebra questions

Not affiliated with the College Board. SAT is a trademark of the College Board.