document.write( "Question 34925: I have to solve each problem then check my answer to be sure it is reasonable. Here's the problem:
\n" ); document.write( " A ten-gallon aquarium holding African cichlids is 3 inches higher than it is wide. It's length is 21 inches, and its volume is 2730 cubic inches. What are the height and width of the aquarium?\r
\n" ); document.write( "\n" ); document.write( "I have set it up to look like this:
\n" ); document.write( " (x-7)~2 + (x+1)~2 + x~2 then I have gotten that figured out to x~2-14x+49+x~2+2x+1=x~2 that is where I get stuck after subtracting the x~2 to get it on the same side as the rest of the equation.
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Algebra.Com's Answer #21171 by mbarugel(146)\"\" \"About 
You can put this solution on YOUR website!
Hello!
\n" ); document.write( "Let's call X to the width of the aquarium. We know that its height must be X+3. Also, its length is 21. Volume is calculated as width*height*length. So we get the following equation:\r
\n" ); document.write( "\n" ); document.write( "\"X%28X%2B3%2921+=+2730\"
\n" ); document.write( "\"X%28X%2B3%29+=+2730%2F21+=+130\"
\n" ); document.write( "\"X%5E2+%2B+3X+=+130\"
\n" ); document.write( "\"X%5E2+%2B+3X+-+130+=+0\"\r
\n" ); document.write( "\n" ); document.write( "Now we can solve this quadratic equation using the standard procedure:\r
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Solved by pluggable solver: SOLVE quadratic equation (work shown, graph etc)
Quadratic equation \"ax%5E2%2Bbx%2Bc=0\" (in our case \"1x%5E2%2B3x%2B-130+=+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=%283%29%5E2-4%2A1%2A-130=529\".
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\n" ); document.write( " Discriminant d=529 is greater than zero. That means that there are two solutions: \"+x%5B12%5D+=+%28-3%2B-sqrt%28+529+%29%29%2F2%5Ca\".
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\n" ); document.write( " \"x%5B1%5D+=+%28-%283%29%2Bsqrt%28+529+%29%29%2F2%5C1+=+10\"
\n" ); document.write( " \"x%5B2%5D+=+%28-%283%29-sqrt%28+529+%29%29%2F2%5C1+=+-13\"
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\n" ); document.write( " Quadratic expression \"1x%5E2%2B3x%2B-130\" can be factored:
\n" ); document.write( " \"1x%5E2%2B3x%2B-130+=+%28x-10%29%2A%28x--13%29\"
\n" ); document.write( " Again, the answer is: 10, -13.\n" ); document.write( "Here's your graph:
\n" ); document.write( "\"graph%28+500%2C+500%2C+-10%2C+10%2C+-20%2C+20%2C+1%2Ax%5E2%2B3%2Ax%2B-130+%29\"

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\n" ); document.write( "\n" ); document.write( "As you can see the two solution are 10 and -13. We can disregard the -13 because width can't be negative. So we conclude that the width of the aquarium is 10 inches. Therefore, its height must be 13 inches.\r
\n" ); document.write( "\n" ); document.write( "You can check that \"10%2A13%2A21+=+2730\"\r
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\n" ); document.write( "\n" ); document.write( "I hope this helps!
\n" ); document.write( "Get more answers at Online Math Answers.com!
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