What is a related sentences for this equation? a - +5 =+35

Do you mean a minus a positive 5 and it will equal to a positive 35.

If that is so, then it is simple, you need to find the unknown (a) by making it as a subject and removing other numbers to one side like this:

a-(+5)=+35

a-5=+35

a=+35+5

= +40

So, a equals to a positive 40/ plus 40