The correct answer is: $x = -2$
Explanation
Let $x$ be the unknown number. “Twenty more than a number is eighteen” translates to the equation $x + 20 = 18$. Solve this equation to find $x$.
Steps:
- Write the equation: $x + 20 = 18$
- Subtract 20 from both sides: $x = 18 – 20$
- Compute the result: $x = -2$
Therefore, the number is $-2$.