Question

Difficulty: EasyExponents, Radicals, and Algebraic Expressions

What is the value of the expression 38+38+3834\frac{3^8 + 3^8 + 3^8}{3^4}?

  1. A
    343^4
  2. 353^5Answer
  3. C
    383^8
  4. D
    3123^{12}
  5. E
    3203^{20}

Answer

353^5
The correct answer is 353^5. Adding three identical values 38+38+383^8 + 3^8 + 3^8 is equivalent to 3×383 \times 3^8, which equals 393^9. Dividing 393^9 by 343^4 gives 394=353^{9-4} = 3^5.

Step-by-Step Solution

1
Simplify the numerator by combining like terms
38+38+38=338=3138=31+8=393^8 + 3^8 + 3^8 = 3 \cdot 3^8 = 3^1 \cdot 3^8 = 3^{1+8} = 3^9
Repeated addition of 33 identical terms is equivalent to multiplying one term by 33.
2
Apply the quotient rule for exponents
3934=394=35\frac{3^9}{3^4} = 3^{9-4} = 3^5
When dividing exponential terms with the same base, subtract the exponent of the denominator from the exponent of the numerator.

Key Concept

Combining like exponential terms using multiplication rules and applying the quotient rule for exponents
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