Final answer:
The expression -5 * sqrt(4x^2) simplifies to -10x because sqrt(4x^2) is 2x, and when multiplied by -5, it yields -10x.
Step-by-step explanation:
The student has asked for the simplified form of the expression -5 * sqrt(4x^2), given that x is greater than or equal to 0. To simplify this expression, we first take the square root of 4x^2, which simplifies to 2x because squaring 2x yields 4x^2 (x² = √x).
Since x is non-negative, we can directly take the absolute value of x when we take the square root of x². Multiplying this by -5 gives us -10x, which is the simplified form of the given expression. Therefore, the correct answer is option a, -10x.