The image contains a mathematical expression that appears to be a matrix or a complex fraction. The numbers and symbols present are: a vertical line with numbers 9, 7 below it, followed by a colon, then 1, 3. Above this is a horizontal line with 18 on the left and 11 on the right, enclosed in parentheses. Above that is a plus sign, and above that is -2. There is also text 'rre:' at the top.

Looks like we have a mathematical expression here, and maybe some text at the top that doesn't seem to be part of the math problem. Let's break down what we see:

• There's text that reads 'rre:' at the top. This doesn't look like it's related to the numbers.
• We have a structure that looks like a matrix or a nested fraction. Let's see if we can interpret it as a calculation.
• On the left side, we have the numbers 9 and 7 stacked vertically, with a vertical line separating them. Below that, we see a colon (:), then the numbers 1 and 3. This part might represent division or a ratio: 9:1:3 with a 7 somehow involved, but the arrangement is a bit unusual.
• Enclosed in parentheses, we have 18 on the left and 11 on the right, separated by a vertical line. This could be interpreted as a fraction 18/11 or perhaps elements of a matrix.
• Above this parenthesized part, there's a plus sign (+).
• And above the plus sign, there's the number -2.

Putting it all together, it's difficult to give a single numerical answer without more context on how these elements are meant to be combined. It could be:

• A matrix where the vertical lines are separators and the parentheses indicate a sub-matrix or a specific operation.
• A complex fraction where operations are nested.
• A sequence of operations where the order is indicated by the layout.

If this is a matrix, the dimensions and the operations between elements would need to be defined. If it's a fraction, the division lines would need to be clearer.

Could you provide more context on what this represents or what needs to be calculated?