Final answer:
The expression (q^2r + s^2t)(q^4r^2 - 6q^2rs^2t + s^4t^2) factors as (q^2r + s^2t)(q^2r - s^2t)(q^2r + s^2t), which corresponds to option A.
Step-by-step explanation:
The student asked to factor the expression (q^2r + s^2t)(q^4r^2 - 6q^2rs^2t + s^4t^2). This can be seen as a product of a binomial and a trinomial. When we look at the trinomial, we can recognize it as a form of a squared binomial, specifically the square of (q^2r - s^2t), because:
- The first term, q^4r^2, is the square of q^2r.
- The last term, s^4t^2, is the square of s^2t.
- The middle term, -6q^2rs^2t, is negative twice the product of q^2r and s^2t.
Thus, the trinomial factors as (q^2r - s^2t)^2. Hence, the entire expression factors as option A: (q^2r + s^2t)(q^2r - s^2t)(q^2r + s^2t).