How do i solve for x with mixture word problems

Well, solving X works different ways in different situations. Say the problem is 3x=6 you have to figure out what to multiply to get the end answer. Now, say it is 2+x=8 what can you add to 2 in order to get 8? Another way is if it says 8+2=x you have to figure out what 8 plus 2 is and that is what X will be. I really hope this helps! :)

45 is the only number in both sets