Q28 of 35 Page 4

Solve the following questions.

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

B = A =

BA =


BA =


Now, we can see that it is BA = 6I. where I is the unit Matrix


Or, B – 1 =


Now the given equation can be written as:



A X B


Or, X = B – 1A


=



=


X =


Hence, x = – 8,y = – 15 and z =

More from this chapter

All 35 →
26

Solve the following system of equations by matrix method:

x – y + 2z = 7


3x + 4y – 5z = – 5


2x – y + 3z = 12

 27

If , find A – 1 and hence solve the system of linear equations:2 x – 3 y + 5z = 11, 3x + 2y – 4z = – 5, x + y – 2z = – 3

 29

If a, b and c are all non-zero and , then prove that .

 30

Find the adjoint of the matrix and hence show that A(adj A) = |A| I3.