Answer:
The correct answer is D. 16 + 4 - 1 = 20 - 1
Explanation:
Option A is not a true equation because 16 + 4 - 1 = 19 and not 20.
Option B is not a true equation because we're using the relational sign "less than" that is used by inequations or inequalities.
Option C is not a true equation because 16 + 4 - 1 = 19 and is not equal to 19 - 1 = 18.
Finally, option D is a true equation because 16 + 4 - 1 = 19 and is equal to 20 - 1 = 19.
The correct answer is D. 16 + 4 - 1 = 20 - 1