2) -3 - 9 = -12 (this is the answer because whenever there are two of the same signs, - and -, you have to multiply the signs, so - times - is equal to a +, therefore the equation will change into 3+9 which equals 12. Once you have 12, put the sign that the bigger number has. 9 has a minus sign in front of it which makes the +12 turn into -12)