Given find BA and use this to solve the system of equations y + 2z = 7, x – y = 3, 2x + 3y + 4z = 17.


We have,





BA = 6I …(i)


Now, given system of equations is:


y + 2z = 7,


x – y = 3,


2x + 3y + 4z = 17


So,



Applying R1 R2, we get



Applying R2 R3, we get



Now, …(ii)


So, BA = 6I [from eq(i)]



and



Now, putting the value of B-1, in eq. (ii), we get






x = 4 , y = 2 and z = -1


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