Answer:

Step-by-step explanation:
Given : 
To Find : Which represents the empirical formula for
?
Solution:
Definition of Empirical Formula - A formula that gives the simplest whole-number ratio of atoms in a compound.

To reduce it in simplest form
Divide the subscript numbers by 3
So, the resultant : 
Thus the empirical formula for
:

Answer:
Step-by-step explanation:
(i)

(ii)
x=5 ==> y=2*5²=50
(iii)

Answer:
greatest factor of 72 and 81 is 9.
Step-by-step explanation:
i got this because 9 is the greatest number when multiplied that will go into both 72 and 81. i solved this by comparing the multiples of 72 and 82.
hope this helped :))