Question

solve the following pair of linear equations for x and y by Cramer's rule :x-y=4 2x+y=2​

Answer 1

Step-by-step explanation:

Given, x+y=4,2x+y=3

Using Cramers rule, find the determinant of the coefficient matrix,

D=

1

2

1

1 =1×1−(2×1) =1−2 =−1

Secondly, find the determinant of x coefficient matrix,

D

x

= 4

3

1

1

=4×1−(3×1) =4−3=1

Similarly, find the determinant of y coefficient matrix,

D

y

=

1

2

4

3

=3×1−(2×4) =3−8=−5

Applying Cramer's rule,

x=

D

D

x

∴x=

−1

1

=−1

y=

D

D

y

∴y=

−1

−5

=5

Therefore, x=−1,y=5