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If 18^ = 5 -1 4 , then what is the value of 81^ ?

Options

  1. A3+ 5 + 5- 5 4
  2. B3+ 5 + 5+ 5 4
  3. C3- 5 + 5- 5 4
  4. D3+ 5 - 5- 5 4

Correct answer

A. 3+ 5 + 5- 5 4

Step-by-step solution

aligned & 18^ = 5 -1 4 & x ^2=4^2-( 5 -1)^2 & x = 10+2 5 & 18^ = 10+2 5 4 & 2 ^2 9-1= 10+2 5 4 & ^2 9= 10+2 5 +4 8 & ^2 81= 4+ 10+2 5 8 aligned After squaring all the options available, we come to a conclusion that option (1) is correct.

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