document.write( "Question 616816: the question on my review is asking me i am thinking of two numbers whose sum is 21 and whose difference is 5. let x be the first number and y be the second number. and solve for x and y how would i go about solving the question? and thank you for helping \n" ); document.write( "
Algebra.Com's Answer #387920 by nerdybill(7384)\"\" \"About 
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two numbers whose sum is 21 and whose difference is 5. let x be the first number and y be the second number. and solve for x and y how would i go about solving the question?
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\n" ); document.write( "Let x = one number
\n" ); document.write( "and y = second number
\n" ); document.write( "then from \"two numbers whose sum is 21\" we have
\n" ); document.write( "x+y = 21 (equation 1)
\n" ); document.write( ".
\n" ); document.write( "from: \"and whose difference is 5\"
\n" ); document.write( "x-y = 5 (equation 2)
\n" ); document.write( ".
\n" ); document.write( "Using the \"addition method\" combine both equations:
\n" ); document.write( "x+y = 21
\n" ); document.write( "x-y = 5
\n" ); document.write( "--------
\n" ); document.write( "2x = 26
\n" ); document.write( "x = 13
\n" ); document.write( ".
\n" ); document.write( "Second number, substitute above into:
\n" ); document.write( "x+y = 21
\n" ); document.write( "13+y = 21
\n" ); document.write( "y = 21-13
\n" ); document.write( "y = 8
\n" ); document.write( ".
\n" ); document.write( "Answer: 8 and 13
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