Lets say i have a question, for example,

Now if i wanted to show my entire work for this question, i would start off like this:

Now lets assume i want to show every single step afterwards...how do i use latex such that all my further work will start with an equal sign but IN LINE my first equal sign so such that i WOULDNT need to repeat the original question everytime (for it to align)

I hope this is understandable :P

Thanks

PS. I know this shouldn't be here...but lets face it...placing it in the right sections get little/no attention.