Final answer:
To find the leading coefficient when adding the polynomials (-7x+7) and (-6x-5), combine like terms to get -13x+2. The leading coefficient is -13, which also fits where the question mark is, making answer A correct.
Step-by-step explanation:
When you add the two polynomials (-7x+7) and (-6x-5), you combine like terms, which are the terms that contain the same variables raised to the same power. In this case, you will combine the x terms and the constant terms separately. The x terms are -7x and -6x, which add up to -13x.
The constant terms are +7 and -5, which add up to +2. Therefore, the addition of these two polynomials results in -13x+2. As such, the leading coefficient of the polynomial is -13, and the question mark, which stands for the coefficient of the x term, should be -13 as well. Therefore, the correct answer is A. Leading coefficient: -13, ? = -13.