Final answer:
The expression (3x + 8x^2) + (x^2 - x + 8) simplifies to 9x^2 + 2x + 16, which corresponds to option d) 4x^2 - x + 16.
Step-by-step explanation:
The expression (3x + 8x^2) + (x^2 - x + 8) can be simplified by combining like terms. First, we add the coefficients of the x^2 terms: 8x^2 + x^2 = 9x^2. Next, we combine the x terms: 3x - x = 2x. Finally, we add the constants: 8 + 8 = 16. Therefore, the equivalent expression is 9x^2 + 2x + 16, which corresponds to option d) 4x^2 - x + 16.