Final answer:
The value of ac for the quadratic expression 9x^2 - 16 is -144. The value of b is 0, as it represents the coefficient of x, which is absent in the expression. Therefore, we do not need two numbers that multiply to ac and add to b; the expression is factored using the difference of squares as (3x + 4)(3x - 4).
Step-by-step explanation:
The polynomial 9x2 − 16 is a quadratic expression that can be factored using the difference of squares method. To answer the questions:
- The value of ac is the product of the coefficient of x2 and the constant term, which in this case is 9 × (− 16) = − 144.
- The value of b in the standard form ax2 + bx + c is the coefficient of x, which is 0 since there is no x term in the original expression.
- To factor, we need two numbers that multiply to ac (which is − 144) and add up to b (which is 0). However, this step is not applicable as the polynomial is already in the form a2 − b2 and will be factored as a difference of squares.
- The factored form of the polynomial is (3x + 4)(3x − 4).