we can't solve that unless m+5 is equal to something. for example, if m+5=0 then the problem would be m=0-5.
but since yor question is just a variable and a number. (a variable of which we don't know the quantity.)
thats why your question will never ever change.
Um. Your awnser will depend on the variable. If you are counting on the m in E=mc2 that has no fixed value. If the varible is five quadrillion then your awnser is five quadrillion and five. If your variable is -40 then your awnser is -35. IT all depends on the variable. So nobody can awnser the question unless you say what 5 is. This might come as a surprise but to a mathmatitian it is pretty obvious. Don't think I'm going at you though. Maybe you just put it to see how many people would put a loooooooong awnser like I did. Whatever the reason this is my awnser.