Notice the function f(x) = (x - 4)³ that a value '4' is subtracted from 'x' ⇒ This means the function f(x) is translated four units to the right.
Then the function f(x) = ¹/₂ (x - 4)³, the function (x - 4)³ is halved vertically ⇒ Half the y-coordinate
Then the function f(x) = ¹/₂ (x - 4)³ + 5 that a value '5' is added to ¹/₂ (x - 4)³ ⇒ This means the function f(x) is translated five units up
So the order of transformation that is happening to f(x) = x³ is translation four units to the right, half the y-coordinate, then translate 5 units up.
When you subtract and add what is in the parentheses you would get -15 so I’m guessing he didn’t go from left to right when working inside the parentheses but when you solve the whole problem out you would get the answer: -41.25 If I missed something or you need me to show the work just let me know but I hope this helps !