Multiple choice general knowledge math & puzzles

For what value of k will the two equations 2x + 4 = 4(x - 2) and -x + k = 2x - 1 have the same solution?

  1. 2

  2. 17

  3. -1

  4. 20
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Solve the first equation: $2x + 4 = 4x - 8 \Rightarrow 12 = 2x \Rightarrow x = 6$. Substitute $x = 6$ into the second equation: $-6 + k = 2(6) - 1 \Rightarrow -6 + k = 11 \Rightarrow k = 17$.

Keep practicing — related questions