<u>Answer:</u>
The correct answer option is 'then'.
<u>Step-by-step explanation:</u>
The "to prove" part of the information is the 'then' of the "if-then" statement.
For example, we have this problem:

If
, then find the value of y.
Here in this problem, we are asked that 'if' the value of x is true then prove it by substituting in the value.
that question doesnt make sense!
All you have to do is find the relationships between the top and bottom and then find how they all r in common
7800 because it grows 300 per 2 hours so 3000 + 4800 = 7800