Final answer:
Upon subtracting −7n² from 2n−1, we combine the terms to get 7n² + 2n − 1, which does not match any of the provided answer choices, indicating a possible mistake in the question or the options.
Step-by-step explanation:
To answer the question of subtracting −7n² from 2n−1, we treat the expression as a subtraction problem, subtracting each term separately. Since there are no like terms, we simply combine the individual terms. This gives us:
(2n−1) − (−7n²) = 2n − 1 + 7n²
Notice that we changed the sign of the second expression due to the subtraction. Combining the similar terms, we get:
− 7n² (since there's no n² term in the first expression to combine it with) and 2n − 1 (since there's no n term or constant to combine these with).
Therefore, the answer is 7n² + 2n − 1. However, this answer is not present in the provided choices. It looks like there might have been a mistake with the options or the problem itself. As a result, the correct answer does not match any of the options given: (a) −9n³, (b) 9n+3, (c) 9n−1, or (d) 9n−3.