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What is 3 +2 equal to if (2 i +6 j +27 k ) ( i + j + k ) is a null vector?

Options

  1. A36
  2. B33
  3. C30
  4. D27

Correct answer

A. 36

Step-by-step solution

Given that, (2 i +6 j +27 k ) ( i + j + k )=0 aligned & | array ccc i & j & k 2 & 6 & 27 1 & & array |=0 & i (6 -27 )- j (2 -27)+ k (2 -6)=0 aligned Comparing both sides of above equation, we get:- aligned & 6 -27 =0 2 =9 & 2 -27=0 = 27 2 and 2 -6=0 =3 aligned So, 3 +2 =3 3+2 27 2 =9+27=36

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