document.write( "Question 540359: The sum of the reciprocals of two numbers is 16/15 and the second number is 1 larger thank the first. Find the two numbers? \n" ); document.write( "
Algebra.Com's Answer #353673 by oberobic(2304)\"\" \"About 
You can put this solution on YOUR website!
The two numbers can be defined as:
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\n" ); document.write( "x+1
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\n" ); document.write( "so their reciprocals are:
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\n" ); document.write( "1/x + 1/(x+1) = 16/15
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\n" ); document.write( "((x+1)+x)/(x*(x+1) = 16/15
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\n" ); document.write( "15((x+1)+x) = 16(x*(x+1))
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\n" ); document.write( "15x + 15 + 15x = 16(x^2 +x)
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\n" ); document.write( "30x + 15 = 16x^2 +16x
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\n" ); document.write( "0 = 16x^2 -14x -15
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\n" ); document.write( "16x^2 -14x -15 = 0
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\n" ); document.write( "(16x+10)(x-3/2) = 0
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\n" ); document.write( "Check with FOIL.
\n" ); document.write( "16x^2 -24x +10x -15
\n" ); document.write( "Correct
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\n" ); document.write( "So, x = -5/8 or x=3/2
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\n" ); document.write( "\"+graph%28500%2C500%2C-5%2C5%2C-20%2C20%2C16%2Ax%5E2-14%2Ax-15%29+\"
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\n" ); document.write( "Or you could solve with quadratic equation.
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Solved by pluggable solver: SOLVE quadratic equation with variable
Quadratic equation \"ax%5E2%2Bbx%2Bc=0\" (in our case \"16x%5E2%2B-14x%2B-15+=+0\") has the following solutons:
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\n" ); document.write( " \"x%5B12%5D+=+%28b%2B-sqrt%28+b%5E2-4ac+%29%29%2F2%5Ca\"
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\n" ); document.write( " For these solutions to exist, the discriminant \"b%5E2-4ac\" should not be a negative number.
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\n" ); document.write( " First, we need to compute the discriminant \"b%5E2-4ac\": \"b%5E2-4ac=%28-14%29%5E2-4%2A16%2A-15=1156\".
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\n" ); document.write( " Discriminant d=1156 is greater than zero. That means that there are two solutions: \"+x%5B12%5D+=+%28--14%2B-sqrt%28+1156+%29%29%2F2%5Ca\".
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\n" ); document.write( " \"x%5B1%5D+=+%28-%28-14%29%2Bsqrt%28+1156+%29%29%2F2%5C16+=+1.5\"
\n" ); document.write( " \"x%5B2%5D+=+%28-%28-14%29-sqrt%28+1156+%29%29%2F2%5C16+=+-0.625\"
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\n" ); document.write( " Quadratic expression \"16x%5E2%2B-14x%2B-15\" can be factored:
\n" ); document.write( " \"16x%5E2%2B-14x%2B-15+=+16%28x-1.5%29%2A%28x--0.625%29\"
\n" ); document.write( " Again, the answer is: 1.5, -0.625.\n" ); document.write( "Here's your graph:
\n" ); document.write( "\"graph%28+500%2C+500%2C+-10%2C+10%2C+-20%2C+20%2C+16%2Ax%5E2%2B-14%2Ax%2B-15+%29\"

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