So I have this one photo of my midterm material, but stupid me didn't check it first when I took it and the photo turned out to be very blurred and it's impossible to read the text. Is it possible to fix it?
Once taken, a blurred picture is composed by individual pixels disposed in a way that give this distortion effect.
Some software algorithms are capable of reducing this effect when it is mild. They rely on a sort of automatic boundary recognition. Simplifying, when they see a difference in colors, they assume it is the edge of an object, and therefore they try to modify local pixels to reduce their color spread – which sometimes gives an effective blur reduction. An example is the unsharp mask in Photoshop:
Filter --> Sharpen --> Unsharp mask
While you could try this command, I fear that you will not get anything good from this specific picture.
Yes, to some extent. See also: Can anyone recommend *freeware* to reduce motion blur by deconvolution?
Explaination if you are familiar with maths: information is definitively lost with ordinary bluring (out of focus, motion blur) because this corresponds to multiplying the source image spectrum by a filter having zero value in the high frequency, so all the details disappear. To cancel a filtering, you can divide by the filter spectrum, execepted when it's zero (one can't divide by zero).
Still, in the domain of digital photography several researchers have proposed effective solution based on "coded aperture" : things added to the lens or camera to subtily structure the blur, so that the blurring spectrum is never zero and thus can be reversed. But in your case it's too late :-/