SOLUTION: Use Cramer's Rule, if applicable, to solve the system. 3x - 4y - 12 = 0 5x + 2y + 6 = 0

Algebra ->  Matrices-and-determiminant -> SOLUTION: Use Cramer's Rule, if applicable, to solve the system. 3x - 4y - 12 = 0 5x + 2y + 6 = 0      Log On


   

Question 315233: Use Cramer's Rule, if applicable, to solve the system.
3x - 4y - 12 = 0
5x + 2y + 6 = 0
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
[A]=%28matrix%282%2C2%2C3%2C-4%2C5%2C2%29%29
[b]=%28matrix%282%2C1%2C12%2C-6%29%29
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Find the determinant of [A].
det[A]=3%282%29-%285%29%28-4%29=26
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Replace the first column of [A] with [b]
[Ax]=%28matrix%282%2C2%2C12%2C-4%2C-6%2C2%29%29
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Calculate this determinant.
det[Ax]=12%282%29-%28-6%29%28-4%29=0
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Calculate x.
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x=det[Ax]/det[A]
x=0%2F26
highlight%28+x=0%29
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Replace the second column of [A] with [b]
[Ay]=%28matrix%282%2C2%2C3%2C12%2C5%2C-6%29%29
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Calculate this determinant.
det[Ax]=%283%29%28-6%29-5%2812%29=-78
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Calculate y.
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y=det[Ay]/det[A]
y=-78%2F26
highlight%28y=-3%29