I don't understand how to get the formula and how to solve part b In 1989 527,000 people worked in the air transportation industry. In 2005, the...

I don't understand how to get the formula and how to solve part b

In 1989 527,000 people worked in the air transportation industry. In 2005​, the number was 477,000.

​(a) Find a linear equation giving the number of employees in the air transportation industry in terms of​ x, the number of years since

1989.

​(b) Assuming the equation remains valid in the​ future, in what year will there be

440,000 employees of the air transportation​ industry?