The answer is a. -4 and 4. The absolute value of -4 is it's opposite, 4. And the absolute value of 4 is it's positive version, the same exact thing, 4.
Grandpa ernie is shrinking! over the past 4 years his height decreased by a total of 2.4 cm. it decreased by the same amount each year. what was the change in grandpa ernie's height each year