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How do you solve a substitution problem using matrices?
\n" ); document.write( "ex.... 5x+2y=-8 and 4x+3y+2
\n" ); document.write( "5x+2y=-8
\n" ); document.write( "4x+3y=-2
\n" ); document.write( "Soln:
\n" ); document.write( "I am new to this group, so i will not be able to write matrices like (). will try to explain:
\n" ); document.write( "Here you will use cramer's Rule like this:
\n" ); document.write( "You will create three matrices. One with the elements (row wise)
\n" ); document.write( "1st row: 5 2
\n" ); document.write( "2nd row: 4 3
\n" ); document.write( "you will calculate the value of determinant(D) as (5*3 minus 4*2)=7
\n" ); document.write( "then we will replace first column i.e. 5 and 4 with -8 and 2
\n" ); document.write( "so it will be like
\n" ); document.write( "1st row: -8 2
\n" ); document.write( "2nd row: -2 3
\n" ); document.write( "again we will calucate the value and call it as D1: -8*3 minus -2*2
\n" ); document.write( "so D1=-20
\n" ); document.write( "now we will calculate D2 by replacing 2nd column with -8 and 2
\n" ); document.write( "so matrix will be like
\n" ); document.write( "1st row: 5 -8
\n" ); document.write( "2nd row: 4 -2
\n" ); document.write( "so D2=5*(-2) minus 4*(-8)=22\r
\n" ); document.write( "\n" ); document.write( "now we have D=7,D1=-20,D2=22
\n" ); document.write( "and x=D1/D and y=D2/D.\r
\n" ); document.write( "\n" ); document.write( "so x=-20/7 and y=22/7\r
\n" ); document.write( "\n" ); document.write( "Hope it will be clear \n" ); document.write( "