SOLUTION: Please help me solve {{{ 3x-2y=7 }}} using Cramer's rule. {{{ 5x+7y=4 }}} What I have tried is. Dx=|7 -2| Dy= |3 -7|

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Question 845527: Please help me solve using Cramer's rule.

What I have tried is.

Dx=|7 -2| Dy= |3 -7|
|4 7| = 49-(-8) |5 4| 12-(-35)
________ -------- = 57/31 _________= -------- = 47/31
|3 -2| 21-(10) |3 -7| 21-(-10)
|5 7| |4 7|

The answers I get wont work when I try and plug them in. Is there a step I am missing?
Answer by ewatrrr(24785)   (Show Source): You can put this solution on YOUR website!
 

Hi,

= 

Yes D = 31 = 21+10

          x = 57/31

        y = -23/31

CHECKING our answer***

 3x-2y= 7

 

Wish You the Best in your Studies.

 

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