Intermediate Algebra for College Students (7th Edition)

RECALL: $a-(-b)=a+(b)$ Thus, $-16 -(-30) = -16+30$ The numbers being added have different signs. This means that to find their sum, their absolute values will be subtracted. Since 30 has a bigger absolute value than $-16$, we know that the sum will have the same sign as $30$, which is positive. Thus, $-16-(-30)$ will result in a positive number.