document.write( "Question 935728: http://postimg.org/image/55lbvtaxl/\r
\n" ); document.write( "\n" ); document.write( "this puzzle \n" ); document.write( "

Algebra.Com's Answer #569033 by MathLover1(20855) $\"\"$ $\"About$

You can put this solution on YOUR website!
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\n" ); document.write( "\n" ); document.write( "it should be $\"9\"$ \r
\n" ); document.write( "\n" ); document.write( "as I see, there is a pattern: start in left vertices,subtract a number from second point, and add the number from third point, and put result in the middle \r
\n" ); document.write( "\n" ); document.write( "first triangle: $\"%287-4%29%2B9=3%2B9=12\"$
\n" ); document.write( "second triangle: $\"%281-1%29%2B4=0%2B4=4\"$ \r
\n" ); document.write( "\n" ); document.write( "third triangle: $\"%286-2%29%2B5=4%2B5=9\"$ \n" ); document.write( "

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