Question

What are the zeros of the graphed function y = 1/3 (x + 3)(x + 5)?

Answer 1

One factor will be zero, hence y will be zero, when x=-3.

The other factor will be zero, hence y will be zero, when x=-5.

The zeros of the function are x ∈ {-5, -3}.

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This solution makes use of the "zero product rule," which states a product is zero if and only if one or more factors is zero.