Answer:[(2x^2 + 5x) + (4x^2 – 4x)] + 5x^3 = (2x^2 + 5x) + [(4x^2 – 4x) + 5x^3] Step-by-step explanation:The associative property of addition states: (A +B) + C = A + (B + C). That means, it doesn't matter which addition you make first, the final result remains the same. In this problem, A = (2x^2 + 5x), B = (4x^2 – 4x) and C = 5x^3. So, adding A to B and its result to C is the same as adding B to C and its result to A.