document.write( "Question 495943: A square has a perimeter of 100 cm and its area is 9x^2 + 12x + 4 cm^2. What is x? \n" ); document.write( "
Algebra.Com's Answer #336275 by nerdybill(7384)\"\" \"About 
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A square has a perimeter of 100 cm and its area is 9x^2 + 12x + 4 cm^2. What is x?
\n" ); document.write( "Since the perimeter is 100 cm
\n" ); document.write( "each side is 100/4 = 24 cm
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\n" ); document.write( "area = 24^2
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\n" ); document.write( "24^2 = 9x^2 + 12x + 4
\n" ); document.write( "576 = 9x^2 + 12x + 4
\n" ); document.write( "0 = 9x^2 + 12x - 572
\n" ); document.write( "apply quadratic formula to get:
\n" ); document.write( "x = {7.33, -8.67}
\n" ); document.write( "we can toss out the negative solution leaving:
\n" ); document.write( "x = 7.33
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\n" ); document.write( "details of quadratic follows:
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Solved by pluggable solver: SOLVE quadratic equation with variable
Quadratic equation \"ax%5E2%2Bbx%2Bc=0\" (in our case \"9x%5E2%2B12x%2B-572+=+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=%2812%29%5E2-4%2A9%2A-572=20736\".
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\n" ); document.write( " Discriminant d=20736 is greater than zero. That means that there are two solutions: \"+x%5B12%5D+=+%28-12%2B-sqrt%28+20736+%29%29%2F2%5Ca\".
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\n" ); document.write( " \"x%5B1%5D+=+%28-%2812%29%2Bsqrt%28+20736+%29%29%2F2%5C9+=+7.33333333333333\"
\n" ); document.write( " \"x%5B2%5D+=+%28-%2812%29-sqrt%28+20736+%29%29%2F2%5C9+=+-8.66666666666667\"
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\n" ); document.write( " Quadratic expression \"9x%5E2%2B12x%2B-572\" can be factored:
\n" ); document.write( " \"9x%5E2%2B12x%2B-572+=+9%28x-7.33333333333333%29%2A%28x--8.66666666666667%29\"
\n" ); document.write( " Again, the answer is: 7.33333333333333, -8.66666666666667.\n" ); document.write( "Here's your graph:
\n" ); document.write( "\"graph%28+500%2C+500%2C+-10%2C+10%2C+-20%2C+20%2C+9%2Ax%5E2%2B12%2Ax%2B-572+%29\"
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