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Question

7x+2y=-3
x-3y=-7
Solve using Gaussian method, Matrix. (pls show step to step explanation)
Comment on type of solution unique, infinite....

Answer 1

7x + 2y = -3
x - 3y = -7

Putting this into matrix form we get:
[7 2 | -3]
[1 -3 | -7]

Swap the rows to make it a bit easier:
[1 -3 | -7]
[7 2 | -3]

Subtract seven times the first row from the second:
[1 -3 | -7]
[0 23 | 46]

Divide the second row by 23:
[1 -3 | -7]
[0 1 | 2]

Add three times the second row to the first:
[1 0 | -1]
[0 1 | 2]

which corresponds to
x = -1, y = 2

so we have a unique solution.

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