To expand and write an equivalent expression of -1/2(-2x + 4y), you can distribute the -1/2 to each term inside the parentheses. Here's the step-by-step process:
-1/2(-2x + 4y) = -1/2 * -2x + -1/2 * 4y
-1/2(-2x + 4y) = x - 2y
Therefore, an equivalent expression of -1/2(-2x + 4y) is x - 2y.
