Basic College Mathematics (10th Edition)

(a) The answers are similar because their absolute values are the same. The answers only differ in their signs. (b) When you switch the order of the numbers in a subtraction problem, the answer becomes the opposite (additive inverse) of the original answer. In symbols, for any real numbers $a$ and $b$, $a-b = -(b-a)$
From Exercise 98, we have the following answers: \begin{array}{cc}&\space-3-5=-8; &5-(-3)=8 \\& \space -4-(-6)=2; &-6-(-4)=-2 \\& \space 3-10=-7; &10-3=7 \end{array} (a) The answers are similar because their absolute values are the same. The answers only differ in their signs. (b) When you switch the order of the numbers in a subtraction problem, the answer becomes the opposite (additive inverse) of the original answer. In symbols, for any real numbers $a$ and $b$, $a-b = -(b-a)$