Write as a single matrix : `(1 - 2 " "3 ) ({:(2,-1,5),(0,2,4),(-7,5,0):})- (2" " - 5 " "7)`

Answer

To solve the problem, we need to express the given expression as a single matrix. The expression is:

\[ (1 - 2 \quad 3) \cdot \begin{pmatrix} 2 & -1 & 5 \\ 0 & 2 & 4 \\ -7 & 5 & 0 \end{pmatrix} - (2 \quad -5 \quad 7) \]

### Step 1: Identify the matrices involved

We have two matrices:
1. A row matrix \( A = (1, -2, 3) \)
2. A square matrix \( B = \begin{pmatrix} 2 & -1 & 5 \\ 0 & 2 & 4 \\ -7 & 5 & 0 \end{pmatrix} \)
3. Another row matrix \( C = (2, -5, 7) \)

### Step 2: Perform the matrix multiplication \( A \cdot B \)

To find \( A \cdot B \), we will calculate each element of the resulting matrix.

- **First element**:
\[ 1 \cdot 2 + (-2) \cdot 0 + 3 \cdot (-7) = 2 + 0 - 21 = -19 \]

- **Second element**:
\[ 1 \cdot (-1) + (-2) \cdot 2 + 3 \cdot 5 = -1 - 4 + 15 = 10 \]

- **Third element**:
\[ 1 \cdot 5 + (-2) \cdot 4 + 3 \cdot 0 = 5 - 8 + 0 = -3 \]

Thus, the result of the multiplication \( A \cdot B \) is:
\[ A \cdot B = (-19, 10, -3) \]

### Step 3: Subtract matrix \( C \) from the result of \( A \cdot B \)

Now we need to subtract matrix \( C \) from the result of \( A \cdot B \):
\[ (-19, 10, -3) - (2, -5, 7) \]

We perform the subtraction element-wise:
- **First element**:
\[ -19 - 2 = -21 \]

- **Second element**:
\[ 10 - (-5) = 10 + 5 = 15 \]

- **Third element**:
\[ -3 - 7 = -10 \]

### Final Result

Thus, the final matrix is:
\[ \begin{pmatrix} -21 & 15 & -10 \end{pmatrix} \]