Answer: Keegan is correct. None of the expressions are equivalent to one another.
The order of operations, PEMDAS, tells us that we do exponents first before addition. This is because the "E" in PEMDAS comes before the "A".
If we wanted to cube all of "6+4", then we would need to say "the quantity 6 plus 4 cubed" or something like "the cube of the sum of 6 and 4".
As the "Model It" sections show, none of the expressions result in the same value. Michael gets 1000, Morgan gets 280, while Keegan gets 70. Therefore, none of the three expressions are equivalent to one another.