document.write( "Question 110062: Find all solutions to the equation.
\n" ); document.write( "r(squared)-8t=-15
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Algebra.Com's Answer #80192 by bucky(2189)\"\" \"About 
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Given the equation:
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\n" ); document.write( "\"t%5E2+-8t+=+-15\"
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\n" ); document.write( "Begin by collecting all the terms on the left side of the equation and getting a zero on the
\n" ); document.write( "right side. You can do this by adding +15 to both sides to get:
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\n" ); document.write( "\"t%5E2+-8t+%2B+15+=+0\"
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\n" ); document.write( "Note that the left side of this equation factors and after factoring the equation becomes:
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\n" ); document.write( "\"%28t+-+5%29%2A%28t+-+3%29=+0\"
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\n" ); document.write( "This equation will be true if either of the two factors on the left side is equal to zero.
\n" ); document.write( "This is the case because multiplication by zero on the left side makes the entire left
\n" ); document.write( "side equal to zero ... and therefore, it is equal to the right side.
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\n" ); document.write( "So, one at a time, set the two factors equal to zero to solve for t.
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\n" ); document.write( "\"t+-+5+=+0\"
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\n" ); document.write( "Add 5 to both sides and you get:
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\n" ); document.write( "\"t+=+5\"
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\n" ); document.write( "Next:
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\n" ); document.write( "\"t+-+3+=+0\"
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\n" ); document.write( "Add 3 to both sides and you get:
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\n" ); document.write( "\"t+=+3\"
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\n" ); document.write( "The two answers to this problem are t = 5 and t = 3. Let's check them by returning to
\n" ); document.write( "the given equation, substituting these values, and seeing if the equation balances.
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\n" ); document.write( "Start with:
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\n" ); document.write( "\"t%5E2+-8t+=+-15\"
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\n" ); document.write( "First substitute 5 for t and the left side of the equation becomes:
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\n" ); document.write( "\"5%5E2+-+8%2A5+=+25+-+40+=+-15\"
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\n" ); document.write( "So when t = 5 the left side of the equation becomes -15 and this equals the right side.
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\n" ); document.write( "Next substitute 3 for t and the left side of the equation is:
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\n" ); document.write( "\"3%5E2+-+8%2A3+=+9+-+24+=+-15\"
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\n" ); document.write( "As before, when t = 3 the left side of the equation is -15 and this equals the right side.
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\n" ); document.write( "So we can conclude that t = 5 and t = 3 are the correct answers to this problem.
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\n" ); document.write( "Hope this helps you to understand this problem.
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