1) \( \frac{27^{3-2 x} \cdot 9^{x-1}}{81^{2 x}} \) 2) \( \frac{6 \cdot 5^{x+1}-2 \cdot 5^{x-2}}{5^{x+3}} \) 3) \( \frac{2^{2009}-2^{2012}}{2^{2010}} \)
Real Tutor Solution
Answer
Solution
Reviewed and approved by the UpStudy tutoring team
Extra Insights
To simplify these expressions, we can use the properties of exponents and the fact that we can represent different bases as powers of the same base where applicable. 1) \( \frac{27^{3-2 x} \cdot 9^{x-1}}{81^{2 x}} \) First, express 27, 9, and 81 in terms of base 3: \( 27 = 3^3 \), \( 9 = 3^2 \), \( 81 = 3^4 \). So we can rewrite the expression as: \[ \frac{(3^3)^{3-2x} \cdot (3^2)^{x-1}}{(3^4)^{2x}} = \frac{3^{9-6x} \cdot 3^{2x-2}}{3^{8x}} = 3^{(9-6x + 2x - 2 - 8x)} = 3^{-5x + 7}. \] 2) \( \frac{6 \cdot 5^{x+1}-2 \cdot 5^{x-2}}{5^{x+3}} \) Factor out \( 5^{x-2} \) from the numerator: \[ 6 \cdot 5^{x+1} - 2 \cdot 5^{x-2} = 5^{x-2} \cdot (6 \cdot 5^3 - 2) = 5^{x-2} \cdot (6 \cdot 125 - 2) = 5^{x-2} \cdot 748. \] Thus, \[ \frac{5^{x-2} \cdot 748}{5^{x+3}} = 748 \cdot \frac{1}{5^5} = \frac{748}{5^5}. \] 3) \( \frac{2^{2009}-2^{2012}}{2^{2010}} \) Factor \( 2^{2009} \) out of the numerator: \[ \frac{2^{2009} (1 - 2^3)}{2^{2010}} = \frac{2^{2009} \cdot (-7)}{2^{2010}} = -7 \frac{2^{2009}}{2^{2010}} = -\frac{7}{2}. \] So the simplified results are: 1) \( 3^{-5x + 7} \) 2) \( \frac{748}{5^5} \) 3) \( -\frac{7}{2} \)