document.write( "Question 156797: The height of a triangle is 2 millimeter less than the base. If the area is 60 square millimeters, find the base \n" ); document.write( "

Algebra.Com's Answer #115606 by jojo14344(1513) $\"\"$ $\"About$

You can put this solution on YOUR website!
We know $\"Area%5BT%5D=%281%2F2%29bh\"$ Sustituting when $\"h=b-2\"$ , height is 2mm less than the base
\n" ); document.write( " $\"60=%281%2F2%29%28b%29%28b-2%29\"$ ------------------------> working eqn
\n" ); document.write( " $\"60=%281%2F2%29%28b%5E2-2b%29\"$ , cross multiply
\n" ); document.write( " $\"120=b%5E2-2b\"$ ---> $\"b%5E2-2b-120=0\"$
\n" ); document.write( "Solve by QUADRATIC, $\"a=1\"$ , $\"b=-2\"$ , & $\"c=-120\"$
\n" ); document.write( " $\"x=%28-b%2B-sqrt%28b%5E2-4ac%29%29%2F%282a%29\"$
\n" ); document.write( " $\"x=%28-%28-2%29%2B-sqrt%28-2%5E2-4%2A1%2A-120%29%29%2F%282%2A1%29\"$
\n" ); document.write( " $\"x=%282%2B-sqrt%284%2B480%29%29%2F2=%282%2B-sqrt%28484%29%29%2F2\"$
\n" ); document.write( " $\"x=%282%2B-22%29%2F2\"$
\n" ); document.write( "2 values: $\"x=%282%2B22%29%2F2\"$ = $\"24%2F2=12mm\"$ BASE
\n" ); document.write( " $\"x=%282-22%29%2F2\"$ = $\"%28-20%2F2%29=%28-10mm%29\"$ , DON'T USE
\n" ); document.write( "In doubt? Go back working eqn:
\n" ); document.write( " $\"60=%281%2F2%29%2812%29%2812-2%29\"$
\n" ); document.write( " $\"60=%281%2F2%29%2812%29%2810%29\"$
\n" ); document.write( " $\"60=%281%2F2%29%28120%29\"$
\n" ); document.write( " $\"60=60\"$
\n" ); document.write( "Thank you,
\n" ); document.write( "Jojo
\n" ); document.write( " \n" ); document.write( "

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