Answer: Yes
But forth power, not root. Root only works for square root.
Selection C is appropriate.
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C = (2A+B)/3 = (2(-3, 6) +(6, -3))/3 = (0, 3).
D is the same thing, but with the coordinates swapped, hence (3, 0).
The answer is 1.3. You round 1.3056 by using place value.