5.5 in fraction is 5 1/2
hope that helps :)
1. 160 2. 520 3.240 hopefully they are right
So we have 299790000, we want to have only one digit in front of the decimal, 2.9979x10^9
hope this helps :)
The answer is 9.2, because when the number behind the number being rounded is 5 or above, you round up. if the number was 9.14, it would be rounded down to 9.1 :)

So; the answer is: A. 5x-2y=1