document.write( "Question 957519: the base of a triangle exceeds twice its altitude by 18m. If the area of the triangle be360 sq.m . What is its altitude?
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Algebra.Com's Answer #585124 by macston(5194)\"\" \"About 
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A=area=360 sq m; h=altitude; b=base=2h+18m
\n" ); document.write( "\"A=%281%2F2%29bh\" Substitute for b.
\n" ); document.write( "\"360m%5E2=%281%2F2%29%282h%2B18%29%28h%29\" Multiply each side by 2.
\n" ); document.write( "\"720m%5E2=2h%5E2%2B18h\" Subtract 720 m^2 from each side
\n" ); document.write( "\"0=2h%5E2%2B18h-720m%5E2\"\n" ); document.write( "\n" ); document.write( " \n" ); document.write( "\n" ); document.write( "
Solved by pluggable solver: SOLVE quadratic equation with variable
Quadratic equation \"ah%5E2%2Bbh%2Bc=0\" (in our case \"2h%5E2%2B18h%2B-720+=+0\") has the following solutons:
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\n" ); document.write( " \"h%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=%2818%29%5E2-4%2A2%2A-720=6084\".
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\n" ); document.write( " Discriminant d=6084 is greater than zero. That means that there are two solutions: \"+x%5B12%5D+=+%28-18%2B-sqrt%28+6084+%29%29%2F2%5Ca\".
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\n" ); document.write( " \"h%5B1%5D+=+%28-%2818%29%2Bsqrt%28+6084+%29%29%2F2%5C2+=+15\"
\n" ); document.write( " \"h%5B2%5D+=+%28-%2818%29-sqrt%28+6084+%29%29%2F2%5C2+=+-24\"
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\n" ); document.write( " Quadratic expression \"2h%5E2%2B18h%2B-720\" can be factored:
\n" ); document.write( " \"2h%5E2%2B18h%2B-720+=+2%28h-15%29%2A%28h--24%29\"
\n" ); document.write( " Again, the answer is: 15, -24.\n" ); document.write( "Here's your graph:
\n" ); document.write( "\"graph%28+500%2C+500%2C+-10%2C+10%2C+-20%2C+20%2C+2%2Ax%5E2%2B18%2Ax%2B-720+%29\"

\n" ); document.write( "\n" ); document.write( "h=15m ANSWER: The altitude of the triangle is 15 meters.
\n" ); document.write( "CHECK:
\n" ); document.write( "b=2h+18m=2(15m)+18m=48m The base of the triangle is 48 meters.
\n" ); document.write( "A=1/2bh
\n" ); document.write( "360sq m=1/2(48m)(15m)
\n" ); document.write( "360 sq m=360 sq m
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