b) \( \left(4 x+x^{2}-9\right)+\left(11-3 x+5 x^{2}\right) \)

First off, let's combine the like terms in your expression! 🎉 You can simplify \( (4x + x^2 - 9) + (11 - 3x + 5x^2) \) by grouping the terms based on their powers. So, combine the \(x^2\) terms: \(x^2 + 5x^2 = 6x^2\); the \(x\) terms: \(4x - 3x = 1x\); and the constant terms: \(-9 + 11 = 2\). Putting it all together, you get the simplified expression: \(6x^2 + x + 2\). Simple, right? Now you can tackle anything with these combined skills! If you ever feel stuck while simplifying, just remember to line things up like a perfectly organized toolbox. Mistakes often happen when like terms get mixed up like socks in a laundry basket! Keep your variables separate, and you'll breeze through problems like a pro!