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If that is the actual image which you're trying to edit, the reason you can't isolate the text is probably because that is a raster image (a JPG, which often are photos). Inkscape is a vector editor and is not capable of editing a raster image, almost at all. As far as I understand, it might be possible to isolate the text using a raster editor, such as GIMP. But even if you could do that, there would still be another step needed, to make those circles into vector paths.
Or maybe you have an SVG or other vector file that you're working on, but you only showed us in a raster image? That looks like something that might have come in a kit, or maybe you purchased a package online or something? Did it come with any vector files, such as SVG, or DXF, or maybe even PDF, or other?
If so, open that vector file in Inkscape. If not, I guess you are supposed to use that JPG with Inkscape's Path menu > Trace Bitmap (or other auto-trace engine). That will convert all those circles into circular paths, which your machine can easily use to cut.
If truly all you need are random circles, like to make a test run or something, you should know that you can easily make them yourself with Inkscape, and not need to trace the raster image. You might even achieve better accuracy that way. On the other hand, those circles of different sizes in their specific arrangment, would probably be hard to reproduce precisely, manually.
So, circles by themselves - easier and more precise to draw manually than auto-tracing. Many different size circles in that specific pattern - much harder to draw on your own "manually", and better to auto-trace.
Even better yet would be if you received a vector file along with that JPG.
If you auto-trace, then after that you will be able to select that black rectangle with text and delete. Depending on which version of Inkscape you're using, you might need to Ungroup the file, after the trace is finished, before you can select the text box separately.
If you have a vector file, you should be able to select the black text box and delete. Although you might need to Ungroup first. Try this (with either a vector file, or your auto-trace result):
-- click on the black text box and look at the status bar (bottom of window, in the middle area)
If it says "
Path nn nodes in Layer...." you might have it selected already. Look where the bounding box is. That's the dashed line rectangle, which indicates to you what is selected. If the bounding box is much larger than that black box, then probably another step is needed.
-- try Path menu > Break Apart
-- deselect everything (click in any open area of canvas, or this button on the control bar
)
If the status bar says "
Group of nn objects....."
-- click Object menu > Ungroup, or this button on the command bar
, click a few times, until the status bar tells you "No more groups to ungroup"
It might be possible, depending on where the file came from, that you need to do some combination of ungrouping and breaking apart. Just keep your eye to the status bar, and it will guide you