I am still having troulbe with these. Her is another one I am stuck on. I think the prime is getting me.

Factor completely or state that it is prime

x^2 + 9xy + 16y^2

The factors of 16 are:
16 x 1.
8 x 2.
4 x 4.
None of these add together to give 9 so it can't be factored as is. Did you make a typo? Is the 9 a 10 or an 8. It would work then.

Does this mean it is prime? No typo

I don't know your definition of prime but the equation, as is, can't be factored.

To determine if a quadratic expression like x^2 + 9xy + 16y^2 is prime or can be factored, you can follow these steps.

1. Look for common factors: Check if there is a common factor among the coefficients of the terms. In this case, there are no common factors among the coefficients 1, 9, and 16.

2. Check for perfect square trinomial: Look for a pattern where the first and last term are perfect squares and the middle term is the product of the square roots. In this case, the first term x^2 is a perfect square (x^2 = (x)^2) and the last term 16y^2 is also a perfect square ((4y)^2 = 16y^2). However, the middle term 9xy cannot be factored in this way since the square root of 9xy would be 3√xy, which is not a simple monomial.

3. Use factoring techniques: The equation x^2 + 9xy + 16y^2 cannot be factored using simple integer or binomial factoring techniques. You have already checked the possible factor pairs of 16 and found that none of them add up to 9.

4. Conclusion: From the above steps, it can be concluded that the expression x^2 + 9xy + 16y^2 is prime, not able to be factored into simpler algebraic expressions.

It's important to note that "prime" in this context means the expression cannot be factored any further using standard techniques.