document.write( "Question 371206: does this system of equation have a unique solution?
\n" ); document.write( "7x-2y=15
\n" ); document.write( "-28x+8y=7 \n" ); document.write( "

Algebra.Com's Answer #264469 by jsmallt9(3758) $\"\"$ $\"About$

You can put this solution on YOUR website!
Since you posted this problem under \"Matrices and Determinants\" I assume you know what they are.

\n" ); document.write( "The fast way to determine whether or not there is a unique solution is to find the value of the following determinant:
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document.write( "|   7  -2  |\r\n" );
document.write( "| -28   8  |\r\n" );
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\n" ); document.write( "The value of this determinant is 7*8 - (-28)*(-2) = 56 - 56 = 0. Since this determinant is zero there is no unique solution. (If this determinant had worked out to be non-zero, then there would be a unique solution.) \n" ); document.write( "

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