Simplify :
`p^(2)x - 2{px - 3x(x^(2) - bar(3a - x^(2)))}`

Answer

To simplify the expression \( p^2 x - 2(px - 3x(x^2 - (3a - x^2))) \), we will follow the steps outlined below:

### Step 1: Simplify the inner expression
First, we need to simplify the expression inside the parentheses:
\[ 3a - x^2 \]
This expression will remain as it is for now.

### Step 2: Expand the expression
Now we will expand the expression \( -2(px - 3x(x^2 - (3a - x^2))) \):
\[ -2(px - 3x(x^2 - 3a + x^2)) \]
This simplifies to:
\[ -2(px - 3x(2x^2 - 3a)) \]

### Step 3: Distribute the \( -3x \)
Next, we distribute \( -3x \) into \( (2x^2 - 3a) \):
\[ -3x(2x^2) + 9ax = -6x^3 + 9ax \]
So, we update our expression:
\[ -2(px + 6x^3 - 9ax) \]

### Step 4: Distribute the \( -2 \)
Now, we distribute \( -2 \) across \( (px + 6x^3 - 9ax) \):
\[ -2px - 12x^3 + 18ax \]

### Step 5: Combine the terms
Now we combine this with the original expression \( p^2 x \):
\[ p^2 x - 2px - 12x^3 + 18ax \]

### Step 6: Final expression
Thus, the simplified expression is:
\[ p^2 x - 2px + 18ax - 12x^3 \]

### Final Answer
The final simplified expression is:
\[ p^2 x - 2px + 18ax - 12x^3 \]