how to super script sub script del and center a text in html

Text that is used in webpage like X²   Y2 del and center it.So we start from Super script 

The is the syntax of super script tag is ^{affect text}.

This show like that 

The result show that 2 become the super script of X. So if any formula that we can write on webpage by using this tag for power of something.

Sub script is look like Y2 so for this used _{affect text}

After used the tag of sub the result is 

Sub and Super script is like above show.

Now if something written wrong on webpage then we used delete tag<del>affect text</del>.

The h r u wrong because it is meaningless word that shown on webpage

So for delete and write right words used del tag .

then the result is

Now the wrong word is deleted and right word how are you is written on webpage.

The whole words are in left side of webpage if want to center that it will be done by used <center>affect text</center> tag.

Now the result of webpage is look like this.