document.write( "Question 393707: Suppose you are given the sum and the difference of two real numbers. How can you figure out what the numbers are themselves? Explain your reasoning clearly step by step. \n" ); document.write( "
Algebra.Com's Answer #279391 by MathLover1(20855)\"\" \"About 
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\n" ); document.write( "\n" ); document.write( "Suppose you are given the sum of \"two\" real numbers
\n" ); document.write( "first name these numbers like \"x\" and \"y\"\r
\n" ); document.write( "\n" ); document.write( "the sum of them you will write like \"x+%2B+y%7D%7D+and+it+will+be+equal+to+certain+number%2C+for+example+%7B%7B%7B10\"\r
\n" ); document.write( "\n" ); document.write( "write an equation:\r
\n" ); document.write( "\n" ); document.write( "now write the other equation\r
\n" ); document.write( "\n" ); document.write( "\"x+-+y+=+4\"....(2)\r
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\n" ); document.write( "\n" ); document.write( "now you have a system of two equations with two unknown variables\r
\n" ); document.write( "\n" ); document.write( "\"x+%2B+y+=+10\"....(1)...\r
\n" ); document.write( "\n" ); document.write( "\"x+-+y+=+4\"....(2)
\n" ); document.write( "---------------------------\r
\n" ); document.write( "\n" ); document.write( "now take any equation of these two and solve for one variable, for example \"x\"\r
\n" ); document.write( "\n" ); document.write( "\"x+%2B+y+=+10\"....(1)...solve for \"x\"\r
\n" ); document.write( "\n" ); document.write( "\"x+=+10+-+y\"....(1)...now substitute it in second equation \r
\n" ); document.write( "\n" ); document.write( "\"%2810+-+y%29+-+y+=+4\"....(2)and solve for \"y\"\r
\n" ); document.write( "\n" ); document.write( "\"10+-+y+-+y+=+4\"\r
\n" ); document.write( "\n" ); document.write( "\"10+-+2y++=+4\"\r
\n" ); document.write( "\n" ); document.write( "\"10+-+4++=+2y\"\r
\n" ); document.write( "\n" ); document.write( "\"6++=+2y\"\r
\n" ); document.write( "\n" ); document.write( "\"6%2F2++=+2y%2F2\"\r
\n" ); document.write( "\n" ); document.write( "\"3+=+y\"..................now you can find \"x\"\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+10+-+y=+10+-+3+=+7\"\r
\n" ); document.write( "\n" ); document.write( "so, your numbers are \"x=7\" and \"y+=+3\"\r
\n" ); document.write( "\n" ); document.write( "check: plug in values for \"x\" and \"y+\"\r
\n" ); document.write( "\n" ); document.write( "\"x+%2B+y+=+10\"....(1)...\r
\n" ); document.write( "\n" ); document.write( "\"7+%2B+3+=+10\"\r
\n" ); document.write( "\n" ); document.write( "\"10+=+10\"\r
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\n" ); document.write( "\n" ); document.write( "\"x+-+y+=+4\"....(2)\r
\n" ); document.write( "\n" ); document.write( "\"7+-+3+=+4\"\r
\n" ); document.write( "\n" ); document.write( "\"4+=+4\"\r
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