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Examine the consistency of the system of equations. 5x − y + 4z = 5 2x + 3y + 5z = 2 5x − 2y + 6z = −1

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Question

Examine the consistency of the system of equations.

5x − y + 4z = 5

2x + 3y + 5z = 2

5x − 2y + 6z = −1

Sum
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Solution

5x − y + 4z = 5

2x + 3y + 5z = 2

5x − 2y + 6z = −1

`[(5,-1,4),(2,3,5),(5,-2,6)] [(x),(y),(z)] = [(5),(2),(-1)]`

⇒ AX = B

Now, |A| = `|(5,-1,4),(2,3,5),(5,-2,6)|`

= 5(18 + 10) + 1(12 − 25) + 4(−4 − 15)

= 140 − 13 − 76

= 51 ≠ 0

Hence, equations are consistent with a unique solution.

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Chapter 4: Determinants - Exercise 4.6 [Page 136]

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NCERT Mathematics Part 1 and 2 [English] Class 12
Chapter 4 Determinants
Exercise 4.6 | Q 6 | Page 136

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