Solve the following systems of linear equations by Cramer’s rule:

2x + 3y = 10


x + 6y = 4

Given: - Two equations 2x – 3y = 10 and x + 6y = 4


Tip: - Theorem – Cramer’s Rule


Let there be a system of n simultaneous linear equations and with n unknown given by







and let Dj be the determinant obtained from D after replacing the jth column by



Then,


provided that D ≠ 0


Now, here we have


2x + 3y = 10


x + 6y = 4


So by comparing with the theorem, let's find D, D1 and D2



Solving determinant, expanding along 1st row


D = 2(6) – (3)(1)


D = 12 – 3


D = 9


Again,



Solving determinant, expanding along 1st row


D1 = 10(6) – (3)(4)


D = 60 – 12


D = 48


and



Solving determinant, expanding along 1st row


D2 = 2(4) – (10)(1)


D2 = 8 – 10


D2 = – 2


Thus by Cramer’s Rule, we have





and





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