document.write( "Question 550506: HELP!!!!! PLEASE........solve using substitution method....
\n" ); document.write( "8x + 2y = 0
\n" ); document.write( "-7x + y = 22
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Algebra.Com's Answer #358816 by jim_thompson5910(35256)\"\" \"About 
You can put this solution on YOUR website!
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\n" ); document.write( "\n" ); document.write( "Start with the given system of equations:\r
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\n" ); document.write( "\n" ); document.write( "\"system%288x%2B2y=0%2C-7x%2By=22%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 second equation\r
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\n" ); document.write( "\n" ); document.write( "\"-7x%2By=22\" Start with the second equation\r
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\n" ); document.write( "\n" ); document.write( "\"y=22%2B7x\" Add \"7x\" to both sides\r
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\n" ); document.write( "\n" ); document.write( "\"y=7x%2B22\" Rearrange the equation\r
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\n" ); document.write( "\n" ); document.write( "Since \"y=7x%2B22\", we can now replace each \"y\" in the first equation with \"7x%2B22\" to solve for \"x\"\r
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\n" ); document.write( "\n" ); document.write( "\"8x%2B2highlight%28%287x%2B22%29%29=0\" Plug in \"y=7x%2B22\" into the first equation. In other words, replace each \"y\" with \"7x%2B22\". 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( "\"8x%2B%282%29%287%29x%2B%282%29%2822%29=0\" Distribute \"2\" to \"7x%2B22\"\r
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\n" ); document.write( "\n" ); document.write( "\"8x%2B14x%2B44=0\" Multiply\r
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\n" ); document.write( "\n" ); document.write( "\"22x%2B44=0\" Combine like terms on the left side\r
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\n" ); document.write( "\n" ); document.write( "\"22x=0-44\"Subtract 44 from both sides\r
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\n" ); document.write( "\n" ); document.write( "\"22x=-44\" Combine like terms on the right side\r
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\n" ); document.write( "\n" ); document.write( "\"x=%28-44%29%2F%2822%29\" Divide both sides by 22 to isolate x\r
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\n" ); document.write( "\n" ); document.write( "\"x=-2\" Divide\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=-2\"\r
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\n" ); document.write( "\n" ); document.write( "Since we know that \"x=-2\" we can plug it into the equation \"y=7x%2B22\" (remember we previously solved for \"y\" in the first equation).\r
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\n" ); document.write( "\n" ); document.write( "\"y=7x%2B22\" Start with the equation where \"y\" was previously isolated.\r
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\n" ); document.write( "\n" ); document.write( "\"y=7%28-2%29%2B22\" Plug in \"x=-2\"\r
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\n" ); document.write( "\n" ); document.write( "\"y=-14%2B22\" Multiply\r
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\n" ); document.write( "\n" ); document.write( "\"y=8\" Combine like terms \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=8\"\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=-2\" and \"y=8\"\r
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\n" ); document.write( "\n" ); document.write( "which form the point \r
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\n" ); document.write( "\n" ); document.write( "Now let's graph the two equations (if you need help with graphing, check out this solver)\r
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\n" ); document.write( "\n" ); document.write( "From the graph, we can see that the two equations intersect at . This visually verifies our answer.\r
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\n" ); document.write( "\n" ); document.write( " graph of \"-7x%2By=22\" (red) and \"8x%2B2y=0\" (green) and the intersection of the lines (blue circle).\r
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