Question

Difficulty: EasyExponents, Roots, and Powers of Integers

What is the value of 26+26+26+26\sqrt{2^6 + 2^6 + 2^6 + 2^6}?

  1. A
    8
  2. 16Answer
  3. C
    32
  4. D
    64
  5. E
    128

Answer

16
The four identical terms 26+26+26+262^6 + 2^6 + 2^6 + 2^6 sum to 4×264 \times 2^6. Since 4=224 = 2^2, the expression inside the radical becomes 22×26=282^2 \times 2^6 = 2^8. Taking the square root yields 28=24=16\sqrt{2^8} = 2^4 = 16.

Step-by-Step Solution

1
Express the sum of the four identical terms as a product.
26+26+26+26=4×262^6 + 2^6 + 2^6 + 2^6 = 4 \times 2^6
Adding a number to itself 4 times is equivalent to multiplying that number by 4.
2
Convert 4 to a power of 2 and combine exponents.
4×26=22×26=22+6=284 \times 2^6 = 2^2 \times 2^6 = 2^{2+6} = 2^8
When multiplying powers with the same base, add their exponents.
3
Simplify the square root of 282^8.
28=(28)1/2=24=16\sqrt{2^8} = (2^8)^{1/2} = 2^4 = 16
Taking the square root of a power means dividing the exponent by 2.

Key Concept

Factoring identical exponential terms and applying exponent laws to simplify radicals.
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