document.write( "Question 196595: Solve this system using the Substitution Method: \r
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Algebra.Com's Answer #147344 by jim_thompson5910(35256)\"\" \"About 
You can put this solution on YOUR website!
\"x+%2B+y+=+7%2F2\" Start with the first equation.\r
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\n" ); document.write( "\n" ); document.write( "\"2x%2B2y=7\" Multiply every term by 2 to clear out the fraction.\r
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\n" ); document.write( "\n" ); document.write( "So we have the system of equations:\r
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\n" ); document.write( "\n" ); document.write( "\"system%282x%2B2y=7%2C4x-3y=-14%29\"\r
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\n" ); document.write( "\n" ); document.write( "Now in order to solve this system by using substitution, we need to solve (or isolate) one variable. I'm going to solve for y.\r
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\n" ); document.write( "\n" ); document.write( "So let's isolate y in the first equation\r
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\n" ); document.write( "\n" ); document.write( "\"2x%2B2y=7\" Start with the first equation\r
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\n" ); document.write( "\n" ); document.write( "\"2y=7-2x\" Subtract \"2x\" from both sides\r
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\n" ); document.write( "\n" ); document.write( "\"2y=-2x%2B7\" Rearrange the equation\r
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\n" ); document.write( "\n" ); document.write( "\"y=%28-2x%2B7%29%2F%282%29\" Divide both sides by \"2\"\r
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\n" ); document.write( "\n" ); document.write( "\"y=%28%28-2%29%2F%282%29%29x%2B%287%29%2F%282%29\" Break up the fraction\r
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\n" ); document.write( "\n" ); document.write( "\"y=-x%2B7%2F2\" Reduce\r
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\n" ); document.write( "\n" ); document.write( "Since \"y=-x%2B7%2F2\", we can now replace each \"y\" in the second equation with \"-x%2B7%2F2\" to solve for \"x\"\r
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\n" ); document.write( "\n" ); document.write( "\"4x-3highlight%28%28-x%2B7%2F2%29%29=-14\" Plug in \"y=-x%2B7%2F2\" into the second equation. In other words, replace each \"y\" with \"-x%2B7%2F2\". Notice we've eliminated the \"y\" variables. So we now have a simple equation with one unknown.\r
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\n" ); document.write( "\n" ); document.write( "\"4x%2B%28-3%29%28-1%29x%2B%28-3%29%287%2F2%29=-14\" Distribute \"-3\" to \"-x%2B7%2F2\"\r
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\n" ); document.write( "\n" ); document.write( "\"4x%2B3x-21%2F2=-14\" Multiply\r
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\n" ); document.write( "\n" ); document.write( "\"%282%29%284x%2B3x-21%2F2%29=%282%29%28-14%29\" Multiply both sides by the LCM of 2. This will eliminate the fractions (note: if you need help with finding the LCM, check out this solver)\r
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\n" ); document.write( "\n" ); document.write( "\"8x%2B6x-21=-28\" Distribute and multiply the LCM to each side\r
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\n" ); document.write( "\n" ); document.write( "\"14x-21=-28\" Combine like terms on the left side\r
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\n" ); document.write( "\n" ); document.write( "\"14x=-28%2B21\"Add 21 to both sides\r
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\n" ); document.write( "\n" ); document.write( "\"14x=-7\" Combine like terms on the right side\r
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\n" ); document.write( "\n" ); document.write( "\"x=%28-7%29%2F%2814%29\" Divide both sides by 14 to isolate x\r
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\n" ); document.write( "\n" ); document.write( "\"x=-1%2F2\" Reduce\r
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\n" ); document.write( "\n" ); document.write( "-----------------First Answer------------------------------\r
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\n" ); document.write( "\n" ); document.write( "So the first part of our answer is: \"x=-1%2F2\"\r
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\n" ); document.write( "\n" ); document.write( "Since we know that \"x=-1%2F2\" we can plug it into the equation \"y=-x%2B7%2F2\" (remember we previously solved for \"y\" in the first equation).\r
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\n" ); document.write( "\n" ); document.write( "\"y=-x%2B7%2F2\" Start with the equation where \"y\" was previously isolated.\r
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\n" ); document.write( "\n" ); document.write( "\"y=-%28-1%2F2%29%2B7%2F2\" Plug in \"x=-1%2F2\"\r
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\n" ); document.write( "\n" ); document.write( "\"y=1%2F2%2B7%2F2\" Multiply\r
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\n" ); document.write( "\n" ); document.write( "\"y=4\" Combine like terms and reduce. \r
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\n" ); document.write( "\n" ); document.write( "-----------------Second Answer------------------------------\r
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\n" ); document.write( "\n" ); document.write( "So the second part of our answer is: \"y=4\"\r
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\n" ); document.write( "\n" ); document.write( "-----------------Summary------------------------------\r
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\n" ); document.write( "\n" ); document.write( "So our answers are:\r
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\n" ); document.write( "\n" ); document.write( "\"x=-1%2F2\" and \"y=4\"\r
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\n" ); document.write( "\n" ); document.write( "which form the ordered pair
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