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Mathematics

Assertion (A): If we divide 3-2 by 34, we get 93.

Reason (R): (xy)m=ymxm\Big(\dfrac{x}{y}\Big)^{-m} = \dfrac{y^{-m}}{x^{-m}}

  1. A is true, R is false

  2. A is false, R is true

  3. Both A and R are true

  4. Both A and R are false

Indices

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Answer

Solving,

323432436(32)393.\Rightarrow \dfrac{3^{-2}}{3^4} \\[1em] \Rightarrow 3^{-2 - 4} \\[1em] \Rightarrow 3^{-6} \\[1em] \Rightarrow (3^2)^{-3} \\[1em] \Rightarrow 9^{-3}.

∴ Assertion (A) is false.

According to reason (R) :

(xy)m=ymxm\Big(\dfrac{x}{y}\Big)^{-m} = \dfrac{y^{-m}}{x^{-m}}

Solving L.H.S,

(xy)m(yx)m(ymxm)\Rightarrow \Big(\dfrac{x}{y}\Big)^{-m} \\[1em] \Rightarrow \Big(\dfrac{y}{x}\Big)^{m} \\[1em] \Rightarrow \Big(\dfrac{y^m}{x^m}\Big) \\[1em]

Since, L.H.S ≠ R.H.S

∴ Reason (R) is false.

Both A and R are false.

Hence, option 4 is the correct option.

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