In subtraction of integers what you need to always remember is to always make the minus sign as a plus sign and the integer beside will have also the opposite sign it has.then proceed on adding.
(row row row your boat)
same sign keep (sign)and add
different sign subtract
use the sign of the greater number
then you'll be exact
-15 +(7)=?
-15 +7 =8
example
-15-(7)=?
change the minus sign to opposite and change the sign of the integer beside
-15+(-7)=?
same sign keep sign and add
-15+(-7)= -22
