Solve for \( x \) : (a) \( 3^{x}=1 \) (d) \( \left(\frac{1}{9}\right)^{x}=27 \) (g) \( 4\left(\frac{1}{4}\right)^{x-1}=8 \) (j) \( \frac{3^{2 x-1}}{3^{x}}=3 \) (m) \( 8^{-x}-2.4^{x-1}=0 \)
Real Tutor Solution
Answer
Solution
Reviewed and approved by the UpStudy tutoring team
Extra Insights
To solve each of these equations, we can use the properties of exponents and logarithms. Let’s delve into the solutions: (a) \( 3^{x} = 1 \) Since any base raised to the power of 0 equals 1, we know that \( x = 0 \). (d) \( \left(\frac{1}{9}\right)^{x} = 27 \) Rewriting \( \frac{1}{9} \) as \( 9^{-1} \), we have \( (9^{-1})^{x} = 27 \). Since \( 27 = 3^3 \) and \( 9 = 3^2 \), we get \( (3^{-2})^{x} = 3^3 \). Thus, \( -2x = 3 \) or \( x = -\frac{3}{2} \). (g) \( 4\left(\frac{1}{4}\right)^{x-1} = 8 \) This can be rewritten as \( 4 \cdot 4^{-(x-1)} = 8 \), simplifying to \( 4^{1 - (x - 1)} = 8 \) or \( 4^{2 - x} = 2^3 \). Converting bases gives us \( 4^{2 - x} = (2^2)^{2-x} = 2^{2(2-x)} = 2^3 \), leading to \( 2(2-x) = 3 \), from which \( 2 - x = \frac{3}{2} \) and \( x = -\frac{1}{2} \). (j) \( \frac{3^{2x-1}}{3^{x}} = 3 \) We can simplify this to \( 3^{2x - 1 - x} = 3 \) or \( 3^{x - 1} = 3^1 \). Therefore, \( x - 1 = 1 \), giving us \( x = 2 \). (m) \( 8^{-x} - 2 \cdot 4^{x - 1} = 0 \) Rewriting as \( 8^{-x} = 2 \cdot 4^{x - 1} \), and recognizing that \( 8 = 2^3 \) and \( 4 = 2^2 \), we can express that as \( (2^3)^{-x} = 2 \cdot (2^2)^{x-1} \). This leads to \( 2^{-3x} = 2^{1 + 2(x-1)} \), simplifying to \( -3x = 1 + 2x - 2 \), or \( -3x = 2x - 1 \). Therefore, \( -5x = -1 \) gives \( x = \frac{1}{5} \). To recap: - (a) \( x = 0 \) - (d) \( x = -\frac{3}{2} \) - (g) \( x = -\frac{1}{2} \) - (j) \( x = 2 \) - (m) \( x = \frac{1}{5} \)