Final answer:
To complete the square, you take half of the x coefficient and square it. In this case, we get 5 squared, which is 25, suggesting 25 unit tiles should be added to complete the square, assuming one addition of tiles.
Step-by-step explanation:
To complete the square and form a perfect square trinomial expression from (2 + 10x + _______ + x + _______ + x), we first look for the coefficient of the x term which is 10. Following the method to complete the square, we take half of that coefficient, (10/2) = 5, and then square it, giving us 52 = 25. To balance the expression, because we have 'x' three times, we need to divide 25 by 3, giving us approximately 8.333. Since we cannot have a fraction of a unit tile, we round down to 8 tiles per 'x', resulting in needing 24 tiles. However, the question seems to suggest that only whole unit tiles can be used and is likely looking for the result of halving the 10 and then squaring it, which since the options do not match these calculations, assuming we must only add one set of tiles, we would add 25 (which is 52).