(a) TRUE The opposite of a number is basically that number's negative. For example, 2 + (-2) = 0.
(b) FALSE Not always! It depends if the first number is greater or less than the second number. For example, 2 - 3 = -1
(c) FALSE Actually, It's the quite opposite! When a positive integer is multiplied to a negative integer, the product is ALWAYS negative. For example. (-2)*3=-6
(d) FALSE NOOOOOOOOOOOO. Just because the sum of a postive and its oppositie integer is 0, it doesn't mean the product is 0. Remember, the only way to get a product to equal 0 is by multiplying by 0!