Question

Difficulty: MediumEquivalent Algebraic Expressions

If xx and yy are positive numbers, which of the following is equivalent to the expression 36x5y33x(xy3)1/2\frac{\sqrt{36x^5 y^3}}{3x(xy^3)^{1/2}}?

  1. A
    2xx2x\sqrt{x}
  2. 2x2xAnswer
  3. C
    12x12x
  4. D
    2xy2xy

Answer

The expression is equivalent to 2x2x.
To find the equivalent expression, simplify the numerator and the denominator separately. The numerator 36x5y3\sqrt{36x^5 y^3} simplifies to 6x5/2y3/26x^{5/2}y^{3/2}. The denominator 3x(xy3)1/23x(xy^3)^{1/2} simplifies to 3x3/2y3/23x^{3/2}y^{3/2}. Dividing the simplified numerator by the simplified denominator yields 6x5/2y3/23x3/2y3/2=2x\frac{6x^{5/2}y^{3/2}}{3x^{3/2}y^{3/2}} = 2x.

Step-by-Step Solution

1
Convert the radical expression in the numerator to an expression with fractional exponents.
36x5y3=(36x5y3)1/2=6x5/2y3/2\sqrt{36x^5 y^3} = (36x^5 y^3)^{1/2} = 6x^{5/2}y^{3/2}
The square root of a product is the product of the square roots of each factor, where a=a1/2\sqrt{a} = a^{1/2}.
2
Apply exponent rules to simplify the denominator.
3x(xy3)1/2=3x1x1/2y3/2=3x3/2y3/23x(xy^3)^{1/2} = 3x^1 \cdot x^{1/2} y^{3/2} = 3x^{3/2}y^{3/2}
When multiplying terms with the same base, add their exponents (xaxb=xa+bx^a \cdot x^b = x^{a+b}).
3
Divide the simplified numerator by the simplified denominator.
6x5/2y3/23x3/2y3/2=2x5/23/2y3/23/2=2x1y0=2x\frac{6x^{5/2}y^{3/2}}{3x^{3/2}y^{3/2}} = 2x^{5/2 - 3/2}y^{3/2 - 3/2} = 2x^1 y^0 = 2x
When dividing terms with the same base, subtract the exponent of the denominator from the exponent of the numerator (xaxb=xab\frac{x^a}{x^b} = x^{a-b}).

Key Concept

Equivalent Algebraic Expressions
Estimated Time:1m 15s
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