document.write( "Question 963864: Please help with equation please; Using Cramers rule,solve system of equation: {8x+3y=5. And. 4x-3y= 7} \n" ); document.write( "
Algebra.Com's Answer #588851 by rothauserc(4718)\"\" \"About 
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{8x+3y=5. And. 4x-3y= 7}
\n" ); document.write( "Let D be the determinant with all the variables, Dx be the determinant for x and Dy be the determinant for y, then
\n" ); document.write( "D = matrix(row 1 is 8 3, row 2 is 4 -3) = -24 -12 = -36
\n" ); document.write( "Dx = matrix(row 1 is 5 3, row 2 is 7 -3) = -15 -21 = -36
\n" ); document.write( "Dy = matrix(row 1 is 8 5, row 2 is 4 7) = 56 -20 = 36
\n" ); document.write( "x = Dx / D = -36 / -36 = 1
\n" ); document.write( "y = Dy / D = 36 / -36 = -1
\n" ); document.write( "therefore,
\n" ); document.write( "x = 1, y = -1
\n" ); document.write( "check the answer by substituting for x and y in the given equations
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\n" ); document.write( "8(1) +3(-1) = 5
\n" ); document.write( "8 -3 = 5
\n" ); document.write( "5 = 5
\n" ); document.write( "**************************
\n" ); document.write( "4(1) -3(-1) = 7
\n" ); document.write( "4 +3 = 7
\n" ); document.write( "7 = 7
\n" ); document.write( "our answer checks
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