Answer:
C
Step-by-step explanation:
First, factor the original expression:

As we can see, D is the same as above. Eliminate D.
Go through each of the answer choices.
A:

This is equivalent to what we factored. Eliminate A.
B:

This is again equivalent to what we factored. Eliminate B.
C:

This cannot be simplified and it is not equivalent to what we have previously. C is not the equivalent expression.
Answer:
I think it should be 56
You can use Pythagorean theorem to solve
10 squared + 3 squared = x squared
100+9=x squared
109=x squared
square route 109 and x to get
10.44=x