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Question
Find x.
`(- 1/7)^-5 ÷ (- 1/7)^-7 = (-7)^x`
Sum
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Solution
Using law of exponents,
am ÷ an = (a)m – n ...[∵ a is non-zero integer]
Then, `(- 1/7)^(-5 + 7) = (-7)^x`
⇒ `(- 1/7)^2 = (- 7)^x`
⇒ (–7)–2 = (–7)x
On comparing powers of (–7), we get
x = –2
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Chapter 8: Exponents and Powers - Exercise [Page 274]
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