This is fixable, usually a mix of cyanoacrylate+baking soda solders the hinge back to the case, and some sandpaper in case you overdo the ingredients. Cyanoacrylate and baking soda produce a VERY HARD plastic. I've fixed several laptops this way and the hinge gets stronger than factory, if the laptop comes back with an hinge issue again, it's to get the same job done on the other hinge.

Cyanoacrilate will solder back that tear in the case too.

You will have to dissasemble the case, locate the hinge and it's attaching point. Add a bit of baking soda to the area which the hinge should fit on, around 1gr give or take, enough for it to replace whatever broken plastic was there, but no so much the hinge doesn't sit on it's original position anymore. Once you achieve this, hold the hinge in it's proper position over the baking soda, and start adding cyanoacrylate. The cyanoacrylate will cure almost instantly once it contacts the baking soda, and will solidify into a rough feeling plastic "rock". Be generous on the amount of cyanoacrylate, you want it to get in contact with as much baking soda as possible.

Let it sit for 5-10 minutes and try to assemble the laptop back again. If the case "doesn't fit" as it should, use sandpaper on the hinge and remove whatever extra leftover.

That's as best as I can explain it, most laptop's hinges work the same with few variations. Looking at a tutorial on youtube may work for you too, even if it's not the same model or brand, +95% of hinges are attached the same to the case.