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If ( a b )^2+( a b )^2=144 and | b |=4 , then what is the value of | a | ?

Options

  1. A3
  2. B4
  3. C5
  4. D6

Correct answer

A. 3

Step-by-step solution

aligned & Given, ( a b )^2+( a b )^2=144 & | a |^2| ~b |^2 ^2 +| a |^2| ~b |^2 ^2 =144 & | a |^2| ~b |^2=144 & | a |^2 16=144 | a |=3 aligned

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