How Do I Fix My TI-84 Calculator Not Graphing Simultaneous Equations?

[Sniperman724]

I wasn't sure where to lost this thread so I decided to put it in general discussion. So anyway, on my TI-84 graphing calculator I have been having this weird problem, once in a while a setting will change on its own( not sure how) and then the calculator would stop letting me graph simultaneous equations, and would only graph one function at a time. Usually when you hit the y= button, there would be parallel lines to the left of each function line but for the past few weeks that symbol changed into a triangle and an upright rectangle(for lack of a better description) to the left of the function lines. I am really not sure how to change it back to parallel lines again. If you can help me out that would be great :)

Thank you so much!

 

[Sniperman724]

I just cannot figure out how to fix it... :/

 

[niko_bellic]

In one problem I may helpful to you..
If u remove batteries or change batteries while TI calculators are on operation then the settings will be changed to default and whole memory (programs) will be erased.

 

[Sniperman724]

Thank you for your help, When I was playing around with my calculator, i guess i must have hit this program called "transfrm" on accident, so when i uninstalled it, I was able to graph simultaneous equations again, and it fixed all of the other problems as well.