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Express the following equations in matrix form and solve them by method of reduction.x + y + z = 1, 2x + 3y + 2z = 2 and x + y + 2z = 4 - Mathematics and Statistics

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प्रश्न

Express the following equations in matrix form and solve them by method of reduction.

x + y + z = 1, 2x + 3y + 2z = 2 and x + y + 2z = 4

बेरीज

उत्तर

Matrix form of the given system of equations is

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

This is of the for AX =  B,

where A = `[(1, 1, 1),(2, 3, 2),(1, 1, 2)]`, X = `[(x), (y), (z)]` and B = `[(1), (2), (4)]`

Applying R2 → R2 – 2R1 and R3 – R1, we get

`[(1, 1, 1),(0, 1, 0),(0, 0, 1)][(x), (y), (z)] = [(1), (0), (3)]`

Hence, the original matrix A is reduced to an upper triangular matrix.

∴ `[(x + y + z),(0 + y + 0),(0 + 0 + z)] = [(1), (0), (3)]`

∴ By equality of martices, we get

x + y + z = 1       ...(i)

y = 0

z = 3

Substituting y = 0 and z = 3 in equation (i), we get

x + 0 + 3 = 1

∴ x = 1 – 3 = – 2

∴ x = –2, y = 0 and z = 3 is the required solution.

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Application of Matrices
  या प्रश्नात किंवा उत्तरात काही त्रुटी आहे का?
पाठ 2: Matrices - Exercise 2.6 [पृष्ठ ८०]

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