document.write( "Question 476080: Two numbers that have a product of -840 and the sum is -22. \n" ); document.write( "
Algebra.Com's Answer #326945 by bucky(2189)\"\" \"About 
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Let the two numbers be x and y.
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\n" ); document.write( "The product of the two numbers is -840. In equation form this is:
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\n" ); document.write( "\"x%2Ay+=+-840\" <---- first equation
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\n" ); document.write( "The sum of the two numbers is -22. In equation form this is:
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\n" ); document.write( "\"x+%2B+y+=+-22\" <---- second equation
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\n" ); document.write( "In the second equation solve for one of the variables in terms of the other. For example solve for x by subtracting y from both sides of the equation. When you do this subtraction you get:
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\n" ); document.write( "\"x+=+-y+-+22\"
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\n" ); document.write( "Substitute the right side of this equation for x in the first equation. This substitution leads to:
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\n" ); document.write( "\"%28-y-22%29%2Ay+=+-840\"
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\n" ); document.write( "Multiply out the left side by multiplying y times each of the two terms in parentheses to get:
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\n" ); document.write( "\"-y%5E2+-22y+=+-+840\"
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\n" ); document.write( "add 840 to both sides of this equation and you have:
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\n" ); document.write( "\"-y%5E2+-22y+%2B+840+=+0\"
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\n" ); document.write( "To get this into standard quadratic form, multiply both sides (all terms) by -1 and the result is:
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\n" ); document.write( "\"y%5E2+%2B+22y+-+840+=+0\"
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\n" ); document.write( "You can solve this by using the quadratic formula, or you can factor it. The left side factors as shown:
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\n" ); document.write( " in which case \"y+=+-42\" or
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\n" ); document.write( "\"y+-+20+=+0\" in which case \"y+=+%2B20\"
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\n" ); document.write( "Since you now know possible solutions for y, you can return to the second equation and solve for x. Using the second equation, substitute y = -42 and you get for x:
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\n" ); document.write( "\"x+%2B+%28-42%29+=+-22\"
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\n" ); document.write( "Add +42 to both sides and this becomes:
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\n" ); document.write( "\"x+=+42-22\" which simplifies to:
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\n" ); document.write( "\"x+=+20\"
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\n" ); document.write( "So one possible solution to this problem is x = 20 and y = -42
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\n" ); document.write( "Another possible solution occurs when y = +20. You can work this out by solving for x, but you will find that the answer for x is x = -42.
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\n" ); document.write( "The answer now becomes apparent. One of the two numbers is -42 and the other is +20. (Either x = 20 and y = -42 or y = 20 and x = -42).
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\n" ); document.write( "Hope this helps you to understand the process for solving this problem.
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