Simplify each radical expression, if possible:

3 √ 7 - ^4 √ 7

Choices:
A) -2 √ 7
B) -2 ^3 √ 7
C) cannot be simplified

C) cannot be simplified

Explanation

We want to simplify the radicals:

We can rewrite this as exponents:

Since the base are the same but are subtracting, we do not have any rule of indices for subtracting unlike indices .

Therefore the expression cannot be simplified further.