document.write( "Question 318180: 3(x+y)- 4 (y-x)= 19
\n" ); document.write( "4(2x-y) + y = 18 \n" ); document.write( "

Algebra.Com's Answer #228092 by stanbon(75887) $\"\"$ $\"About$

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3(x+y)- 4 (y-x)= 19
\n" ); document.write( "3x+3y -4y + 4x = 19
\n" ); document.write( "7x - y = 19
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\n" ); document.write( "4(2x-y) + y = 18
\n" ); document.write( "8x -4y + y = 18
\n" ); document.write( "8x-3y = 18
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\n" ); document.write( "Solve this system:
\n" ); document.write( "7x - y = 19
\n" ); document.write( "8x - 3y= 18
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\n" ); document.write( "Solve for \"y\" in the 1st equation:
\n" ); document.write( "y = 7x-19
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\n" ); document.write( "Substitute for \"y\" in the 2nd equation and solve for \"x\":
\n" ); document.write( "8x -3*(7x-19) = 18
\n" ); document.write( "---
\n" ); document.write( "8x - 21x + 57 = 18
\n" ); document.write( "-13x = -39
\n" ); document.write( "x = 3
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\n" ); document.write( "Since y = 7x-19, so y = 7*3-19 = 2
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\n" ); document.write( "Cheers,
\n" ); document.write( "Stan H.
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