Final Answer:
The algebraic equation m² = 81 is true when m = 9.
Therefore, correct answer is A. m = 9
Step-by-step explanation:
To find the values that make the equation true, you need to determine the square root of 81, considering both positive and negative roots. In this case, m = pm 9 . However, the question specifies looking for a "true number sentence," which implies considering only the positive root since the equation m² = 81 is satisfied when m = 9.
When dealing with square roots in equations, it's important to consider both positive and negative solutions. However, context matters. In this case, the question is seeking values that make the equation a "true number sentence," which typically implies choosing the positive solution for clarity and relevance to real-world scenarios.
Therefore, correct answer is A. m = 9