Context: The equation $11j + 9k = m$ relates the numbers $j$, $k$, and $m$, and the task is to solve it for $k$ in terms of $j$ and $m$.

Answer: B) $k = \dfrac{m - 11j}{9}$

Why? Subtract $11j$ from both sides to leave the $k$ term alone: $9k = m - 11j$. Dividing both sides by $9$ divides the entire right side, giving $k = \dfrac{m - 11j}{9}$.

Traps:

• A) $k = \dfrac{1}{9}m - 11j$ divides only $m$ by $9$ and leaves $11j$ undivided; the division must apply to the whole side.
• C) $k = 9m - 11j$ multiplies $m$ by $9$ instead of dividing by it, and again leaves $11j$ untouched.
• D) $k = \dfrac{11j - m}{9}$ reverses the order of the subtraction, which flips the sign of the entire result.