First combine like terms (-9n-3n=-12n)
Then, subtract 6n on both sides (to get rid of the 6n) = -18n
Then, add 8 to both sides (does not matter) = 0
Finally divide (answer is 0)
Since you have to mix all of it together, the whole cocktail is 20+10+15=45.
And the portion that is coconut milk is 15ml. So that means there is 15 out of 45 or 15/45 coconut milk in the cocktail. Then the simpelest form is 1/3.
90 square ft (try and look at it like each side is a 2d rectangle, find the areas of the sides and then add them up.)