Answer:
If 
is divisible by 3, the n is also divisible by 3.
Step-by-step explanation:
We will prove this with the help of contrapositive that is we prove that if n is not divisible by 3, then, is not divisible by 3.
Let n not be divisible by 3. Then 
can be written in the form of fraction 
, where x and y are co-prime to each other or in other words the fraction is in lowest form.
Now, squaring
Thus,
It can be clearly seen that the fraction 
is in lowest form.
Hence, is not divisible by 3.
Thus, by contrapositivity if is divisible by 3, the n is also divisible by 3.
40,000 is 10 times as much as 4,000
Step-by-step explanation:
Let x = number of games that Alex played
The total money that he spent C is given by
If he spent $45, then we can write
Solving for x, we get
This means that Alex played 15 games.
Basically put it in a calculator
3 months happens 4 times in a year, and so does the 1/3 foot of erosion. 4 times 1/3 foot = 4/3 feet. That's 1-1/3 feet, or 1 foot 4 inches.
