Chapter 5 - Number Theory and the Real Number System - 5.2 The Integers; Order of Operations - Exercise Set 5.2 - Page 270: 117

It will shrink by 5 years.

To know if your lifespan will stretch or shrink, and by the number of years, add the years of having a blood relative of 95 or older to the years of smoking cigarettes. 10 + (-15) = 10 - 15 = -5 It will shrink by 5 years.