Soru

Zorluk: ZorExponents, Roots, and Scientific Notation

If x=812×461693x = \frac{\sqrt{8^{12} \times 4^6}}{\sqrt[3]{16^9}}, what is the value of x\sqrt{x}?

  1. A
    16
  2. 64Cevap
  3. C
    256
  4. D
    4,096
  5. E
    65,536

Cevap

64
First, convert all bases in the expression to base 2: 812=(23)12=2368^{12} = (2^3)^{12} = 2^{36}, 46=(22)6=2124^6 = (2^2)^6 = 2^{12}, and 169=(24)9=23616^9 = (2^4)^9 = 2^{36}. The numerator becomes 236×212=248=224\sqrt{2^{36} \times 2^{12}} = \sqrt{2^{48}} = 2^{24}. The denominator becomes 2363=212\sqrt[3]{2^{36}} = 2^{12}. Dividing the numerator by the denominator gives x=224212=212x = \frac{2^{24}}{2^{12}} = 2^{12}. Finally, taking the square root of xx yields x=212=26=64\sqrt{x} = \sqrt{2^{12}} = 2^6 = 64.

Adım Adım Çözüm

1
Express each base in the expression (88, 44, and 1616) as a power of 22.
The bases are rewritten as 8=238 = 2^3, 4=224 = 2^2, and 16=2416 = 2^4.
Converting all terms to a common base allows us to apply standard laws of exponents to simplify the expression.
2
Simplify the numerator 812×46\sqrt{8^{12} \times 4^6} using exponent rules.
(23)12×(22)6=236×212=248=224\sqrt{(2^3)^{12} \times (2^2)^6} = \sqrt{2^{36} \times 2^{12}} = \sqrt{2^{48}} = 2^{24}.
We multiply the exponents for the power of a power rule, add the exponents when multiplying powers with the same base, and then divide the exponent by 2 to take the square root.
3
Simplify the denominator 1693\sqrt[3]{16^9} using exponent rules.
(24)93=2363=212\sqrt[3]{(2^4)^9} = \sqrt[3]{2^{36}} = 2^{12}.
We multiply the exponents for the power of a power rule and then divide the exponent by 3 to take the cube root.
4
Evaluate xx by dividing the simplified numerator by the simplified denominator.
x=224212=22412=212x = \frac{2^{24}}{2^{12}} = 2^{24 - 12} = 2^{12}.
We subtract the exponent of the denominator from the exponent of the numerator when dividing powers with the same base.
5
Calculate the value of x\sqrt{x} as requested in the question.
x=212=212/2=26=64\sqrt{x} = \sqrt{2^{12}} = 2^{12/2} = 2^6 = 64.
Taking the square root of a base to a power is equivalent to dividing the exponent by 2.

Anahtar Kavram

Applying properties of exponents and radical operations to simplify rational expressions.
Bu soruyu puanla