document.write( "Question 583654: solve the following by the elimination method 7x-4y=-30 and 3x+4y=10 \n" ); document.write( "

Algebra.Com's Answer #372531 by Maths68(1474) $\"\"$ $\"About$

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$\"7x-4y=-30\"$ ..........(1)
\n" ); document.write( " $\"3x%2B4y=10\"$ ..........(2)
\n" ); document.write( "Add (1) and (2)
\n" ); document.write( " $\"7x-4y=-30\"$
\n" ); document.write( " $\"3x%2B4y=10\"$
\n" ); document.write( "----------------
\n" ); document.write( " $\"10x=-20\"$
\n" ); document.write( " $\"cross%2810%29x%2Fcross%2810%29=cross%28-20%29%2Fcross%2810%29\"$ \r
\n" ); document.write( "\n" ); document.write( " $\"x=-2\"$
\n" ); document.write( "Put the value of x in (2)
\n" ); document.write( " $\"3x%2B4y=10\"$ ..........(2)
\n" ); document.write( " $\"3%28-2%29%2B4y=10\"$
\n" ); document.write( " $\"-6%2B4y=10\"$
\n" ); document.write( " $\"4y=10%2B6\"$
\n" ); document.write( " $\"4y=16\"$ }
\n" ); document.write( " $\"4y%2F4=16%2F4\"$
\n" ); document.write( " $\"cross%284%29y%2Fcross%284%29=cross%2816%29%2Fcross%284%29\"$
\n" ); document.write( " $\"y=4\"$
\n" ); document.write( "x,y=-2,4\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Check
\n" ); document.write( "======
\n" ); document.write( "Put the value of x and y in (1)\r
\n" ); document.write( "\n" ); document.write( " $\"7x-4y=-30\"$ ..........(1)
\n" ); document.write( " $\"7%28-2%29-4%284%29=-30\"$
\n" ); document.write( " $\"-14-16=-30\"$
\n" ); document.write( " $\"-30=-30\"$
\n" ); document.write( "Put the value of x and y in (2)
\n" ); document.write( " $\"3x%2B4y=10\"$ ..........(2)
\n" ); document.write( " $\"3%28-2%29%2B4%284%29=10\"$
\n" ); document.write( " $\"-6%2B16=10\"$
\n" ); document.write( " $\"10=10\"$
\n" ); document.write( " \n" ); document.write( "

\n" );