Final answer:
The solutions for the equation a² = 16 are a = 4 and a = -4. Thus, the correct answers from the given options are a. 4 and c. -4.
Step-by-step explanation:
The student has asked to solve for a where a² = 16. When solving this type of equation, which is a simple quadratic equation, you square root both sides of the equation to find the value of a. In doing so, you must consider both the positive and negative square roots because both (√16) and (-√16) squared will yield 16.
The square root of 16 is 4, so the two possible solutions for a when a² = 16 are
Therefore, the correct answers from the given options are a. 4 and c. -4. Options b. -8 and d. 8 are incorrect because they do not square to 16.