The mathematical expression in your image is:

$B = \frac{2\sqrt{x-3}}{\sqrt{x-1}} + \frac{3 - \sqrt{x}}{x - 1}$ where $x > 0$ and $x \neq 1$.

Let's proceed to simplify this expression. Here's how we can approach it:

1. Simplify the second fraction: We can simplify $\frac{3 - \sqrt{x}}{x - 1}$ by rationalizing the numerator (multiplying both numerator and denominator by $3 + \sqrt{x}$).

2. Simplify the overall expression: After simplifying the second fraction, we can combine it with the first fraction.

Would you like to go through the simplification step-by-step? Let me know if you'd like further details or if you're ready to see the complete solution.