Solve the following systems of homogeneous linear equations by matrix method:

2x – y + 2z = 0


5x + 3y – z = 0


X + 5y – 5z = 0

The system can be written as



A X = 0


Now, |A| = 2(– 15 + 5) + 1(– 25 + 1) + 2(25 – 3)


|A| = – 20 – 24 + 44


|A| = 0


Hence, the system has infinite solutions


Let z = k


2x – y = – 2k


5x + 3y = k



A X = B


|A| = 6 + 5 = 11≠0 So, A – 1 exist


Now adj A = =


X = A – 1 B =


X =


Hence, x = , y = and z = k


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