document.write( "Question 216520: a 13-foot ladder is leaning against a house. the distance from the bottom of the ladder to the house is 7 feet less than the distance from the top of the ladder to the ground. how far is the bottom of the ladder from the house? \n" ); document.write( "
Algebra.Com's Answer #163484 by drj(1380)\"\" \"About 
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A 13-foot ladder is leaning against a house. The distance from the bottom of the ladder to the house is 7 feet less than the distance from the top of the ladder to the ground. How far is the bottom of the ladder from the house?\r
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\n" ); document.write( "\n" ); document.write( "Step 1. Let c=13 as hypotenuse.\r
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\n" ); document.write( "\n" ); document.write( "Step 2. Let \"x\" be the distance from the top of the ladder to the ground\r
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\n" ); document.write( "\n" ); document.write( "Step 3. Let \"y=x-7\" be the distance from the bottom of the ladder to the house\r
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\n" ); document.write( "\n" ); document.write( "Step 4. Use the Pythagorean Theorem which says that the sum of the squares of the legs (x and by)of a right triangle is equal to the sum of the hypotenuse c or \"x%5E2%2By%5E2=c%5E2\"\r
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\n" ); document.write( "\n" ); document.write( "Step 5. Then substitute y of Step 3 into Step 4.\r
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\n" ); document.write( "\n" ); document.write( "\"%28x-7%29%5E2%2Bx%5E2=c%5E2=13%5E2\"\r
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\n" ); document.write( "\n" ); document.write( "\"2x%5E2-14x%2B49=169\"\r
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\n" ); document.write( "\n" ); document.write( "Subtracting 160 from both sides to get a quadratic equation\r
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\n" ); document.write( "\n" ); document.write( "\"2x%5E2-14x%2B49-169=169-169\"\r
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\n" ); document.write( "\n" ); document.write( "\"2x%5E2-14x-120=0\"\r
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\n" ); document.write( "\n" ); document.write( "Step 5. The quadratic formula will be used to sole the equation. The formula is given as\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+\"\r
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\n" ); document.write( "\n" ); document.write( "where a=2, b=-14, and c=-120.\r
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Solved by pluggable solver: SOLVE quadratic equation with variable
Quadratic equation \"ax%5E2%2Bbx%2Bc=0\" (in our case \"2x%5E2%2B-14x%2B-120+=+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%2A2%2A-120=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%5C2+=+12\"
\n" ); document.write( " \"x%5B2%5D+=+%28-%28-14%29-sqrt%28+1156+%29%29%2F2%5C2+=+-5\"
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\n" ); document.write( " Quadratic expression \"2x%5E2%2B-14x%2B-120\" can be factored:
\n" ); document.write( " \"2x%5E2%2B-14x%2B-120+=+2%28x-12%29%2A%28x--5%29\"
\n" ); document.write( " Again, the answer is: 12, -5.\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%2B-14%2Ax%2B-120+%29\"

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\n" ); document.write( "\n" ); document.write( "Pick the solution, \"x=12\" , since we want positive lengths.\r
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\n" ); document.write( "\n" ); document.write( "\"y=x-7=20-7=5\"\r
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\n" ); document.write( "\n" ); document.write( "Step 6. ANSWER: The distance from the bottom of the ladder to the house is 5 feet.\r
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\n" ); document.write( "\n" ); document.write( "I hope the above steps were helpful.\r
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\n" ); document.write( "\n" ); document.write( "For FREE Step-By-Step videos in Introduction to Algebra, please visit \r
\n" ); document.write( "\n" ); document.write( "http://www.FreedomUniversity.TV/courses/IntroAlgebra and for Trigonometry visit \r
\n" ); document.write( "\n" ); document.write( "http://www.FreedomUniversity.TV/courses/Trigonometry.\r
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\n" ); document.write( "\n" ); document.write( "Good luck in your studies!\r
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\n" ); document.write( "\n" ); document.write( "Respectfully,
\n" ); document.write( "Dr J
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