They are described if you read them. The two numbers are the line number and column number so the first is Line 7, Column 24.
Look at line 7 or Line 8, they are invalid C#. Being as you’ve typed “+” and it’s on the same key as what is probably meant to be “=” there then I think you’re just making typos and not following the code you’re copying correctly.
btw
- Why tag with “monodevelop”? You’re clearly using Visual Studio.
- Here’s how you post code on the forums: Using code tags properly