Question

Solve the system using a matrix.
-2x - 3y = -26
3x + 4y = 36
([? ],[_])
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Answer 1

-2x-3y=-26

3x+4y=36

using matrix method

(-2 -3(x = (-26

3 4) y ) 36)

AB=C

multiplying A^-1 on both sides

A^-1AB=A^-1C

IB=A^-1C ........(¡) (AA^-1=I)

determined of A |A|=-8-(-9)=-8+9=1

adjoint of A= (4 3

-3 -2)

now

IB=A-^1C

B=adjoint A/determined of A.C

B=(4 3

-3 -2)/1 .C

B=(4 3 (-26

-3 -2). 36)

B=(-104+108

78-72)

( x (4

y) = 6)

Equating the corresponding elements of equal matrices

:.x=4

:.y=6

so the required value of x and y is 4and6.