Question: Will the hidden lines in this `H1` tag and content section help SEO?
For example:

`<h1>Red Carpet <span style="display:none"> Made to measure floor carpet in England with Premium quality </span></h1>`

Here I only want to show "Red Carpet" and I don't want to show the rest. So if I make other line hidden, will Google still read that lines and give more strength to my page? Is there any benefit that I will get adding hidden content?

Answer: 
Absolutely not, on the contrary, you could be penalized by [cloaking](https://en.wikipedia.org/wiki/Cloaking).

> 
> Cloaking is a search engine optimization (SEO) technique in which the
>  content presented to the search engine spider is different from that
>  presented to the user's browser.
> 
> 
> 

[Google understands CSS styles](https://www.seroundtable.com/google-display-none-20626.html) (especially the ones used to hide content) so that strategy can backfire you easily.
Google does not 'score code' it scores rendered content and placement, little to no weight is assigned to 'styling' because 'design' is subjective, you do not need a word to be in bold or underline for users to take notice. 

Ditch the early era SEO books.