Final answer:
The statement "The first entry in the product Ax is a sum of products" is true. Because the first entry in the product Ax is a sum of products (Option A).
Step-by-step explanation:
When you multiply a matrix, A, by a vector, x, the first entry in the product Ax is typically the sum of the products of the corresponding entries from the first row of A and the vector x. Therefore, the first entry in the product Ax is a sum of products is true.
To express this operation algebraically, if A has a first row represented by a₁₁, a₁₂, ..., a₁ₙ and the vector x is represented by x₁, x₂, ..., xₙ, then the first entry of Aₓ would be a₁₁x₁ + a₁₂x₂ + ... + a₁ₙxₙ.
Thus, the correct answer is A. True, the first entry in the product Ax is a sum of products.