Hi,

From Insert->Picture->Creat Ctrl+T, do you know if is possible to erase something something you wrote? I do not see any erase option...

There is no way to erase something in that type of graphics region.

If you want to have editable images in your worksheet, you can use the image region plugin.

Unfortunately I can't attach the First Steps PDF.
Here is the raw text contents:

5.1 Creating and Adjusting an Image Region
First, you insert an image region: Insert> Image and drag it to the approximate desired
size:

In the placeholder at the bottom left, you can specify the name of an image file. However,
you can also create an empty image file and then edit it directly from SMath.
For this, the context menu (right-click) is important:

Display input data: Here you can disable the display of the placeholder.
Open With: Here you can specify which program should open the image file. The
default is the system’s standard program for the selected file type.
Blank File Type: Selection of the internal file format (default is PNG).
Switch border on/off: Here you can disable the border of the image.


5.2 Editing the Image
Use Context menu> Open With... to select and start a program for editing the file.
Double click on the image region launches the default program for the selected file format.
In the editing program, you create the file contents. Here is an example of what it looks
like in Paint, where a PNG file is being edited:

Then close the program (if you forgot to save, you will be prompted to do so). You may
need to click next to the image in order to see the changes in SMath:

It is best to create the annotations directly in SMath by overlaying formulas on the image.
This ensures a consistent appearance of symbols throughout the worksheet.

Images created in this way are saved with the worksheet and can be edited later. This can
be done by double-clicking on the image or using the Context menu> Open With....
The image will then open in the preset or selected program.