Answer
The answer is $\frac{1+x-2\sqrt x}{1-x} $.
Work Step by Step
The given expression is
$\frac{1-\sqrt x}{1+\sqrt x}$.
Multiply and divide by $1-\sqrt x$
$=\frac{1-\sqrt x}{1+\sqrt x} \cdot \frac{1-\sqrt x}{1-\sqrt x}$
Simplify.
$=\frac{(1-\sqrt x)^2}{1-x} $
Clear the parentheses.
$=\frac{1+x-2\sqrt x}{1-x} $.
