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Solve the following elementary exponential equation.

[tex]\[ 7^{3x-8} = \frac{1}{49} \][/tex]

Answer:

[tex]\[ x = \][/tex]


Sagot :

To solve the equation [tex]\( 7^{3x - 8} = \frac{1}{49} \)[/tex], follow these detailed steps:

1. Rewrite [tex]\( \frac{1}{49} \)[/tex] as a power of 7:
[tex]\[ \frac{1}{49} = 49^{-1} \][/tex]
Since [tex]\( 49 = 7^2 \)[/tex], we can write:
[tex]\[ 49^{-1} = \left( 7^2 \right)^{-1} = 7^{-2} \][/tex]
Therefore, the original equation can be rewritten as:
[tex]\[ 7^{3x - 8} = 7^{-2} \][/tex]

2. Since the bases are the same, set the exponents equal to each other:
[tex]\[ 3x - 8 = -2 \][/tex]

3. Solve for [tex]\( x \)[/tex]:
[tex]\[ 3x - 8 = -2 \][/tex]
Add 8 to both sides:
[tex]\[ 3x - 8 + 8 = -2 + 8 \][/tex]
Simplifying this gives:
[tex]\[ 3x = 6 \][/tex]
Divide both sides by 3:
[tex]\[ x = \frac{6}{3} \][/tex]
Simplifying further:
[tex]\[ x = 2 \][/tex]

Therefore, the solution to the equation [tex]\( 7^{3x - 8} = \frac{1}{49} \)[/tex] is [tex]\( x = 2 \)[/tex].