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Monday, 29 June 2026
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If \(\frac{1}{5^{-y}} = 25(5^{4-2y})\), find the value of y.

If \(\frac{1}{5^{-y}} = 25(5^{4-2y})\), find the value of y.
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  • A 4
  • B 2
  • C -4
  • D -5
Correct Answer: Option B
Explanation:
\(\frac{1}{5^{-y}} = 25(5^{4-2y})\)

\(\implies 5^{y} = (5^{2})(5^{4-2y})\)

\(5^{y} = 5^{2+4-2y}\)

Comparing bases, we have

\(y = 6 - 2y\)

\(3y = 6 \implies y = 2\)

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