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Zorluk: OrtaOperations with Variable Exponents

During a physics calculation, a student models a system's energy output using the following expression, where xx and yy are non-zero variables:

(2x−2y3)34x−4y5 \frac{(2x^{-2}y^3)^3}{4x^{-4}y^5}

What is the fully simplified form of this expression using only positive exponents?

  1. 2y4x2\frac{2y^4}{x^2}Cevap
  2. B
    2y4x10\frac{2y^4}{x^{10}}
  3. C
    y42x2\frac{y^4}{2x^2}
  4. D
    3y42x2\frac{3y^4}{2x^2}

Cevap

2y4x2\frac{2y^4}{x^2}
Applying the power of a product rule to the numerator yields 8x−6y98x^{-6}y^9. Dividing this by the denominator 4x−4y54x^{-4}y^5 involves dividing the coefficients (8/4=28/4 = 2) and subtracting the exponents of like bases. For xx, −6−(−4)=−2-6 - (-4) = -2, and for yy, 9−5=49 - 5 = 4. The resulting expression is 2x−2y42x^{-2}y^4. To represent this with positive exponents, the x−2x^{-2} term is moved to the denominator, giving 2y4x2\frac{2y^4}{x^2}.

Adım Adım Çözüm

1
Apply the power of a product rule to the numerator.
(2x−2y3)3=23⋅(x−2)3⋅(y3)3=8x−6y9(2x^{-2}y^3)^3 = 2^3 \cdot (x^{-2})^3 \cdot (y^3)^3 = 8x^{-6}y^9
The exponent outside the parentheses applies to every individual factor inside.
2
Divide the numerical coefficients.
8÷4=28 \div 4 = 2
Numerical coefficients are handled separately from variables with exponents.
3
Apply the quotient of powers rule to the variables.
x−6−(−4)=x−2x^{-6 - (-4)} = x^{-2} and y9−5=y4y^{9 - 5} = y^4
When dividing like bases, you subtract the denominator's exponent from the numerator's exponent.
4
Combine the results and convert the negative exponent to a positive exponent.
2x−2y4=2y4x22x^{-2}y^4 = \frac{2y^4}{x^2}
Moving a term with a negative exponent to the denominator changes its exponent to positive.

Anahtar Kavram

Simplifying rational algebraic expressions using the power of a product rule, the quotient of powers rule, and negative exponents.
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