SOLUTION: Use Cramer's Rule to solve the system. 6x+12y=33 4x+7y=20

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Question 136141: Use Cramer's Rule to solve the system.
6x+12y=33
4x+7y=20
Answer by solver91311(24713) About Me  (Show Source):
You can put this solution on YOUR website!

You need to create three 2X2 matrices of the form

%28matrix%282%2C2%2Ca%2Cb%2Cc%2Cd%29%29 and the value of this matrix is: ad-cb

The first has the coefficients of the variables:

D=%28matrix%282%2C2%2C6%2C12%2C4%2C7%29%29. Use the formula above to calculate the value of D

The second matrix is the same as the first with the 1st column replaced by constant values on the right side of your equations.

D%5Bx%5D=%28matrix%282%2C2%2C33%2C12%2C20%2C7%29%29. Use the formula above to calculate the value of D%5Bx%5D

D%5By%5D is the same process, but replace the 2nd column with the constant values. Use the formula above to calculate the value of D%5By%5D


Then Cramer's Rule says:

x=D%2FD%5Bx%5D

y=D%2FD%5By%5D

-- if the system is independent. If D,D%5Bx%5D, or D%5By%5D = 0, Cramer's Rule doesn't work.