document.write( "Question 433415: the perimeter is 47, one length is x+4 another one is x+5 the other 3x-2 and the last x^2-2x \n" ); document.write( "
Algebra.Com's Answer #300480 by jorel1380(3719)\"\" \"About 
You can put this solution on YOUR website!
x2-2x+3x-2+x+5+x+4=47
\n" ); document.write( "x2+3x+7=47
\n" ); document.write( "x2+3x-40=0
\n" ); document.write( "(x+8)(x-5)=0
\n" ); document.write( "x=-8,5
\n" ); document.write( "Throwing out the negative answer, we get x=5.
\n" ); document.write( "The sides are 9,10,13,15.
\n" ); document.write( "\n" ); document.write( "\n" ); document.write( " \n" ); document.write( "\n" ); document.write( "
Solved by pluggable solver: SOLVE quadratic equation with variable
Quadratic equation \"ax%5E2%2Bbx%2Bc=0\" (in our case \"1x%5E2%2B3x%2B-40+=+0\") has the following solutons:
\n" ); document.write( "
\n" ); document.write( " \"x%5B12%5D+=+%28b%2B-sqrt%28+b%5E2-4ac+%29%29%2F2%5Ca\"
\n" ); document.write( "
\n" ); document.write( " For these solutions to exist, the discriminant \"b%5E2-4ac\" should not be a negative number.
\n" ); document.write( "
\n" ); document.write( " First, we need to compute the discriminant \"b%5E2-4ac\": \"b%5E2-4ac=%283%29%5E2-4%2A1%2A-40=169\".
\n" ); document.write( "
\n" ); document.write( " Discriminant d=169 is greater than zero. That means that there are two solutions: \"+x%5B12%5D+=+%28-3%2B-sqrt%28+169+%29%29%2F2%5Ca\".
\n" ); document.write( "
\n" ); document.write( " \"x%5B1%5D+=+%28-%283%29%2Bsqrt%28+169+%29%29%2F2%5C1+=+5\"
\n" ); document.write( " \"x%5B2%5D+=+%28-%283%29-sqrt%28+169+%29%29%2F2%5C1+=+-8\"
\n" ); document.write( "
\n" ); document.write( " Quadratic expression \"1x%5E2%2B3x%2B-40\" can be factored:
\n" ); document.write( " \"1x%5E2%2B3x%2B-40+=+1%28x-5%29%2A%28x--8%29\"
\n" ); document.write( " Again, the answer is: 5, -8.\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-40+%29\"
\n" ); document.write( "
\n" ); document.write( "
\n" );