G = 7 + (-6)   G = 1;    Y  =  -8  +  12  Y = 4;   R =  -7 + 5    R = -2;   Notice that  in problem Y = -8 + 12   it is not necessary to put the -8 in parenthesis.  But in problem  G = 7 + (-6)  it was.  This is to avoid confusion.  If we write G = 7 + -6 people might wonder is it a typo, a negative number or a subtraction problem.

Remember the rule when adding numbers: If one number is positive and the other negative, find the difference between the numbers and bring over the sign of the larger number.  return