-18+4+x=19

We are solving for x

first off we add 4 to -18 giving us -14 

(If you are confused of how I got this there will be an explanation below*)

now we have -14+X=19

X will be whatever makes that -14 into 19

So we know we can knock out that -14 by adding 14 so far this makes X=14 

making the total on that side 0

but 0 does not equal 19

now all we have to do is add 19 to X (which is 14) to get our final answer:

33

so X=33

lets plug this in

-14+33=19

if we add a negative number to a positive number it's the same as just subtracting

so 33-14=19

Now that we know our answer is correct we can Use that big ol #2 pencil and add that answer in and do the rest! 

May the odds be ever in your favor

also if you were wondering about the -18+4=-14 here is the explanation

If I borrowed 18 bucks from Benedict cumberbatch I would be -18 dollars in debt

if I payed him 4 dollars I would only be 14 dollars in debt 

get it?

if not then just pm me

Nice answer, Stormegetton......good humor, too !!!