Solve the equation `|(x+a, x,x),(x,x+a, x),(x,x,x+a)|=0`, `a!= 0`

Explanation

To solve the equation \( |(x+a, x, x), (x, x+a, x), (x, x, x+a)| = 0 \) where \( a \neq 0 \), we will follow these steps:

### Step 1: Write the determinant
We start with the determinant:
\[
D = \begin{vmatrix}
x+a & x & x \\
x & x+a & x \\
...