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MHT CET202015 Oct 2020Morning ShiftMathematicsVector AlgebraActual

If a = +5 k , b =2 +3 k , c =4 - +2 k and d = - , then ( c - a ) ( b d )=

Options

  1. A12
  2. B20
  3. C30
  4. D10

Correct answer

A. 12

Step-by-step solution

b d = | array ccc i & j & k 2 & 0 & 3 1 & -1 & 0 array |= i (3)- j (0-3)+ k (-2) b d =3 i +3 j -2 k and c - a =3 i - j -3 k then ( c - a ) ( b d )=3(3)+(-1)(3)+(-3)(-2)=9-3+6=12

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