Let's solve the questions step-by-step.

Part (a): Matrix Details

For each matrix, we need to state:

1. Bilangan baris (number of rows).
2. Bilangan lajur (number of columns).
3. Peringkat matriks (rank of the matrix).

i) $$\begin{bmatrix}

2 & 3 \ -5 \end{bmatrix}$$

• Rows: 2 rows.
• Columns: 1 column.
• Rank: Since all rows are non-zero, the rank is 2.

ii) $$\begin{bmatrix}

2 & 1 & 4 \ -2 & 6 & 5 \end{bmatrix}$$

• Rows: 2 rows.
• Columns: 3 columns.
• Rank: Perform row reduction or determine linear independence. After evaluation, the rank is 2.

iii) $$\begin{bmatrix}

7 & 5 \ -1 & 3 & 5 \ 8 & 1 \end{bmatrix}$$

• Rows: 3 rows.
• Columns: 3 columns.
• Rank: After evaluating the rows for independence, the rank is 3.

Part (b): Specific Elements in Matrix $A$

Given the matrix: