3+8n=-5

if you can answer, can you explain?

To solve for 'n' we need to isolate it, while keeping the equation balanced (i.e. whatever we do, we need to make sure the equals sign is still true). First lets group all the terms without n on one side of the equals sign. To do this we need to cancel out the -3 on the left side. We can do this with a +3, BUT we need to add +3 to both  sides of the equation to keep it balance (i.e. to keep the equal sign true). 




Now we need to get 'n' all by itself. Right now 'n' is multiplied by 8. Just like how we undid a negative with a positive above we can 'undo' multiplication with it's inverse function, division. So, lets' divide by 8, again doing it to both sides:




And there's our answer! Well almost....to be really correct we should simplify that fraction:


And we could of course Write that as:


If we want to check that we got it right we can do that by 'plugging in' our answer back into the original question:




Since -5 does indeed equal -5, the last line of our check is true and we know we got the right answer.