Question

Difficulty: MediumEquivalent Algebraic Expressions

For all positive real numbers xx and yy, the expression (4x3y2)216x8y6\frac{(4x^3 y^2)^2}{\sqrt{16x^8 y^6}} can be written in the equivalent form axbycax^b y^c, where aa, bb, and cc are positive constants. What is the value of a+b+ca + b + c?

Answer: 7

Answer

7
The expression simplifies to 4x2y14x^2 y^1 by applying the power of a product rule to the numerator to get 16x6y416x^6 y^4, and simplifying the radical in the denominator to get 4x4y34x^4 y^3. Dividing the terms yields 4x2y14x^2 y^1. Identifying the coefficients and exponents gives a=4a = 4, b=2b = 2, and c=1c = 1. The sum of these values is 4+2+1=74 + 2 + 1 = 7.

Step-by-Step Solution

1
Simplify the numerator of the expression.
(4x3y2)2=16x6y4(4x^3 y^2)^2 = 16x^6 y^4
Apply the power of a product rule (ab)n=anbn(ab)^n = a^n b^n and the power of a power rule (am)n=amn(a^m)^n = a^{mn}.
2
Simplify the denominator of the expression.
16x8y6=4x4y3\sqrt{16x^8 y^6} = 4x^4 y^3
Take the square root of the coefficient and apply fractional exponent rules for positive variables: 16=4\sqrt{16} = 4, x8=x8/2=x4\sqrt{x^8} = x^{8/2} = x^4, and y6=y6/2=y3\sqrt{y^6} = y^{6/2} = y^3.
3
Divide the numerator by the denominator.
16x6y44x4y3=4x2y1\frac{16x^6 y^4}{4x^4 y^3} = 4x^2 y^1
Divide the coefficients and subtract the exponents of the corresponding variables: 164=4\frac{16}{4} = 4, x64=x2x^{6-4} = x^2, and y43=y1y^{4-3} = y^1.
4
Identify the values of aa, bb, and cc, and sum them.
a=4a = 4, b=2b = 2, c=1c = 1, and a+b+c=7a + b + c = 7
Match the simplified form 4x2y14x^2 y^1 to axbycax^b y^c to find aa, bb, and cc, then calculate their sum.

Key Concept

Simplifying equivalent algebraic expressions using exponent rules and radical properties.
Estimated Time:1m 30s
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