Modern medical advances might mean people could live 200 years. in 2009,, the life expectancy is about 80 years. assume that, due to modern advances, life expectancy gains 5.7 years every decade. from 2009, in how many years would humanity achieve a life expectancy of 110 years?

50 years

Step-by-step explanation:

Let x be the number of decades after 2009 and y be the life expectancy ( in years ) after x decades,

∵ life expectancy gains 5.7 years every decade,

If In 2009, the life expectancy is about 80 years.

So, the life expectancy after x decades,

y = 80 + 5.7x

If y = 110 years,

∴ 110 = 80 + 5.7x

⇒ 110 - 80 = 5.7x

⇒ 30 = 5.7x

⇒ x = = 5.26315789474 ≈ 5

Hence, after 5 decades or 50 years since 2009 the life expectancy would be 110 years.

in simplified version   it would be x ≤-4

step-by-step explanation:

multiply each term in x ≤-4 by -1