Question

Solve the following system of equations by matrix method:

(i) 5x + 7y + 2 = 0

4x + 6y + 3 = 0

(ii) 5x + 2y = 3

3x + 2y = 5

Answer 1

(i) Given as 5x + 7y + 2 = 0 and 4x + 6y + 3 = 0

Above equation can be written as

|A| = 30 - 28 = 2

Therefore, the above system has unique solution given as

X = A-1B

Suppose Cij be the cofactor of aij in A

So, x = 9/2 and y = -7/2

(ii) Given as 5x + 2y = 3

3x + 2y = 5

Above equation can be written as

Here

|A| = 10 - 6 = 4

Therefore, the above system has unique solution given as

X = A-1B

Suppose Cij be the cofactor of aij in A

So, x = -1 and y = 4