The back of my phone is cracked what can you do

Usually yes,but it’s very difficult to do,especially if you haven’t done it before. Since it’s the back,I’d strongly recommend leaving it alone,unless you want to pay a ton of money on a phone that costs less than many out there. I believe they use loca glue(clear glue that solidifies with usb light),as they use it on some lcd screens to hold the digitizer or cover glass on. The back would be hard to replace,and in doing so,you may make it worse,and give up. Any repair place would probably charge more than it’s worth. It shouldn’t be noticeable in a case however.