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Zorluk: OrtaEquivalent Algebraic Expressions

Which of the following expressions is equivalent to (8x6)23(4x2)12(8x^6)^{\frac{2}{3}} \cdot (4x^{-2})^{-\frac{1}{2}} for all positive values of xx?

  1. A
    2x32x^3
  2. B
    2x42x^4
  3. 2x52x^5Cevap
  4. D
    8x58x^5

Cevap

2x52x^5
To find the equivalent expression, simplify each part of the product. The first part, (8x6)23(8x^6)^{\frac{2}{3}}, simplifies to 823x623=4x48^{\frac{2}{3}} \cdot x^{6 \cdot \frac{2}{3}} = 4x^4. The second part, (4x2)12(4x^{-2})^{-\frac{1}{2}}, simplifies to 412x212=12x4^{-\frac{1}{2}} \cdot x^{-2 \cdot -\frac{1}{2}} = \frac{1}{2}x. Multiplying these two simplified expressions gives 4x412x=2x54x^4 \cdot \frac{1}{2}x = 2x^5. This matches the expression 2x52x^5.

Adım Adım Çözüm

1
Simplify the first term, (8x6)23(8x^6)^{\frac{2}{3}}, by distributing the exponent to both the coefficient and the variable.
(8x6)23=823(x6)23=(83)2x623=22x4=4x4(8x^6)^{\frac{2}{3}} = 8^{\frac{2}{3}} \cdot (x^6)^{\frac{2}{3}} = (\sqrt[3]{8})^2 \cdot x^{6 \cdot \frac{2}{3}} = 2^2 \cdot x^4 = 4x^4
The power of a product rule states that (ab)n=anbn(ab)^n = a^n b^n, and the power of a power rule states that (am)n=amn(a^m)^n = a^{mn}.
2
Simplify the second term, (4x2)12(4x^{-2})^{-\frac{1}{2}}, by distributing the exponent to both the coefficient and the variable.
(4x2)12=412(x2)12=14x212=12x1=12x(4x^{-2})^{-\frac{1}{2}} = 4^{-\frac{1}{2}} \cdot (x^{-2})^{-\frac{1}{2}} = \frac{1}{\sqrt{4}} \cdot x^{-2 \cdot -\frac{1}{2}} = \frac{1}{2}x^1 = \frac{1}{2}x
Applying the same power rules, negative exponent properties, and multiplying negative exponents yields a positive exponent: 212=1-2 \cdot -\frac{1}{2} = 1.
3
Multiply the simplified expressions obtained in Step 1 and Step 2.
4x412x=(412)(x4x1)=2x4+1=2x54x^4 \cdot \frac{1}{2}x = (4 \cdot \frac{1}{2}) \cdot (x^4 \cdot x^1) = 2x^{4+1} = 2x^5
Multiply the coefficients and add the exponents of the same base variable according to the product rule aman=am+na^m \cdot a^n = a^{m+n}.

Anahtar Kavram

Simplifying algebraic expressions containing rational and negative exponents by using the rules of exponents.
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