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If 2 A+3 B= [ array ccc 2 & -1 & 4 3 & 2 & 5 array ] and A+2 B= [ array lll 5 & 0 & 3 1 & 6 & 2 array ] , then B=

Options

  1. A[ array ccc 8 & 1 & 2 1 & 10 & 1 array ]
  2. B[ array ccc 8 & 1 & -2 -1 & 10 & -1 array ]
  3. C[ array ccc 8 & 1 & 2 -1 & 10 & -1 array ]
  4. D[ array ccc 8 & -1 & 2 -1 & 10 & -1 array ]

Correct answer

C. [ array ccc 8 & 1 & 2 -1 & 10 & -1 array ]

Step-by-step solution

We have, 2 A+3 B= [ array ccc 2 & -1 & 4 3 & 2 & 5 array ]...(i) and A+2 B= [ array lll 5 & 0 & 3 1 & 6 & 2 array ]...(ii) Multiply Eq. (ii) by 2 , we get 2 A+4 B= [ array ccc 10 & 0 & 6 2 & 12 & 4 array ]...(iii) Now, subtracting Eq. (i) from Eq. (iii), we get B= [ array ccc 10 & 0 & 6 2 & 12 & 4 array ]- [ array ccc 2 & -1 & 4 3 & 2 & 5 array ]= [ array ccc 8 & 1 & 2 -1 & 10 & -1 array ]

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