document.write( "Question 1141867: 4x-3y=-1
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Algebra.Com's Answer #762514 by math_helper(2461) $\"\"$ $\"About$

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4x-3y=-1
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\n" ); document.write( "\n" ); document.write( "Substitution!!!
\n" ); document.write( "how plz
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document.write( "From the first equation, 
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document.write( "  add 3y to each side -->  4x = -1+3y 
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document.write( "  divide each side by 4 -->  x = (-1+3y)/4 = (-1/4) + (3y/4)\r
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document.write( "Substitute the right hand side of this last equation for \"x\" in the 2nd equation:
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document.write( "   3( (-1/4) + (3y/4) )  - y = -2
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document.write( "   
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document.write( "   multiply paren contents by 3 (this is distributive property of multiplication):  
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document.write( "      (-3/4) + (9y/4)  - y = -2
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document.write( "  
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document.write( "   add  3/4 to each side -->  (9y/4) - y = -2 + 3/4
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document.write( "   LHS & RHS over common denom -->   (9y/4)-(4y/4) = (-8/4) + (3/4)\r
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document.write( "   multiply both sides by 4 -->    9y - 4y = -8 + 3
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document.write( "    combine like terms  --->       5y = -5
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document.write( "    divide both sides by 5 --->     y = -1 \r
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document.write( "     substitute y=-1 into one of original two equations --> 3x -(-1) = -2
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document.write( "                      3x + 1 = -2
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document.write( "       subtract 1 from both sides -->  3x = -3
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document.write( "          divide both sides by 3  -->   x = -1
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document.write( "Ans:  x=-1 and y=-1.  
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document.write( "Check by plugging these values into original equations:
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document.write( "     4x - 3y =  4(-1) - 3(-1) = -4 + 3 = -1  (ok)
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document.write( "     3x - y = 3(-1) - (-1) = -3 + 1 = -2  (ok)\r
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document.write( "You're welcome.  \n" );
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