What does 9 plus 6 minus 5 equal? (hi: )

15 point ! ~ see if you know the answer to both you!

Asocial networking site currently has 400,000 active members, and that figure is predicted to increase by 32% each year. the following expression represents the number of active members on the site after t years.

What is the answer to this question? i'm a bit stumped. also how do i do it? 5(x - 4) = 2(x + 5)