Help with full calculations please and thank you

x = 13

Step-by-step explanation:

1. We can tell if the radical is in its simplest form if the square root term is a number that cannot be broken down to give a perfect square factor

what we are saying in this case is that if the number that is under the square root sign is one in which cannot be broken down to give a perfect square or that a perfect square is not its factor. Then it is in the simplest form

2. 512 = 2^(x-4)

512 = 2^9

2^9 = 2^(x-4)

since base is equal, we equate the powers

9 = x - 4

x = 9 + 4

x = 13

step-by-step explanation:

i think it is c, not positive though

step-by-step explanation: