we nee to leave X by itself, in order for us to do that we need to take away the 36.
to take away the 36 all we need to do is the opposite of what is being done, which is in this case is subtraction since what is being done is addition (+36)
X+36=83 -36 -36 (what you do on one side of the parenthesis must be done on the other in order to balance the equation)
The soda is price elastic because if you sell 10 dollars ecah you have an revenue of 20 dollars. And if you shorten the price to 1 dollar and you sell 30 of them you have a revenue of 30 dollars. So the sodas are price elastic.
