11. \( (3 w-5 t)^{2}+w(7 w-8 t) \)

Let's break down that expression! First, you notice the quadratic form in \( (3w - 5t)^2 \). When expanded, it becomes \( 9w^2 - 30wt + 25t^2 \). Now, combine this with \( w(7w - 8t) \), which results in \( 7w^2 - 8wt \). Now, bringing it all together: \[ (3w - 5t)^{2} + w(7w - 8t) = 9w^2 - 30wt + 25t^2 + 7w^2 - 8wt. \] Combine like terms: \[ (9w^2 + 7w^2) + (-30wt - 8wt) + 25t^2 = 16w^2 - 38wt + 25t^2. \] So the final expression simplifies to \( 16w^2 - 38wt + 25t^2 \)! Who knew simplifying could be so satisfying?