I scanned the page out of the book, alittle bit is kinda burly but i'm confused on how they got A_2(B), where we are thinking of the system in matrix form AX = B. One verfies that detA = -127 and det[A_2(B)] = 313, so(adsbygoogle = window.adsbygoogle || []).push({});

x2 = det[A_2(B)]/det(A) = 313/-127 = -313/127;

How did they get B? and det[A_2(B)] here is the picture:

http://img416.imageshack.us/img416/9428/lastscan5eu.jpg [Broken]

thanks.

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# Homework Help: Using cramer's Rule to solve for x2, i'm confused on this example!

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