\( \left\lvert\, \leftarrow \begin{array}{l}\text { Perform the indicated operation and simplify. } \\ -(7 x-3)^{2} \\ -(7 x-3)^{2}=\square \text { (Simplify your answer.) }\end{array}\right. \)

First, let's expand the expression \( -(7x - 3)^{2} \). We start by squaring \( (7x - 3) \): \[ (7x - 3)^{2} = 49x^{2} - 42x + 9. \] Now, applying the negative sign, we have: \[ -(7x - 3)^{2} = -49x^{2} + 42x - 9. \] So the simplified answer is: \[ \square = -49x^{2} + 42x - 9. \] Next, always double-check your signs during distribution and when applying negative signs! A common mistake might be dropping the negative when squaring or incorrectly applying it to individual terms. Remember, careful order of operations helps prevent mishaps!