Aculture started with 5000 bacteria after 2 hours it grew to 6500 predict how mabacteria will be present after 18 hours

In 18 hour it grew 13,500, because it grew 1,500 in 2 hour and if you divide 18 by 2 it is 9 so 1,500 time 2 is 13,500.
hopefully I am correct and this helps you.

In 18 hours there are a total of 13,500 bacteria.

First, you'd find the difference between 6,500 and 5,000 (6,500 - 5,000 = 1,500). Next you'd divide 1,500 by 2 to find how many grow per hour (1,500/2 = 750). Finally, you multiply 750 by 18, to show how many will be present in 18 hours.

I hope this helps!