Amachine does 1000 tasks in 4.3 x 10^-2 seconds. how much task will be done in 2 hours? leave answer in scientific notation.

You need to find out how many times (4.3 x 10^-2 seconds) goes into 2 hours,
and however many times that is, the machine will do that many thousand tasks.
It's just a simple division problem.

2 hours = 7,200 seconds

(7.2 x 10^3 seconds) / (4.3 x 10^-2 seconds) = 1.674 418 605 x 10^5 times (rounded)

The machine completes 1.674 418 60 x 10^8 tasks, and it's working on
the next one when the two hours expire.