"Simplify" usually means "combine like terms, rationalize the denominator, reduce radicals to the greatest extent, cancel common factors from fractions, eliminate parentheses," and the like.
When a function of a single variable is multiplied by a single constant, there is no simplification that can be done.
18cos(Ф)
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If your ∅ is supposed to be zero, then cos(0) = 1 and it simplifies to 18.
The correct answer is $216 because when 7 tickets cost $126 each ticket was $18. I know this because 126/7 is 18. Now to find out how much 12 tickets cost you multiply 18x12 to get 216.
