document.write( "Question 622302: hello sir/madam i am shreya from new delhi i want to ask if a,b,c are all non zero and a+b+c=0 prove that a^square/bc+b^square/ca+c^square/ab=3 \n" ); document.write( "
Algebra.Com's Answer #391321 by jsmallt9(3758)\"\" \"About 
You can put this solution on YOUR website!
There may be a simpler way for this but here goes...

\n" ); document.write( "If
\n" ); document.write( "\"a%2Bb%2Bc+=+0\"
\n" ); document.write( "then
\n" ); document.write( "\"%28a%2Bb%2Bc%29%5E3+=+0\"
\n" ); document.write( "To cube the left side I am going to use the \"%28x%2By%29%5E3+=+x%5E3%2B3x%5E2y%2B3xy%5E2%2By%5E3\" pattern with the \"x\" being \"(a+b)\" and the \"y\" being \"c\":
\n" ); document.write( "\"%28a%2Bb%29%5E3+%2B+3%28a%2Bb%29%5E2%2Ac+%2B+3%28a%2Bb%29%2Ac%5E2+%2Bc%5E3+=+0\"
\n" ); document.write( "For the \"%28a%2Bb%29%5E3\" I will use this pattern again:
\n" ); document.write( "
\n" ); document.write( "For the \"%28a%2Bb%29%5E2\" I will use the \"%28x%2By%29%5E2+=+x%5E2%2B2xy%2By%5E2\" pattern:
\n" ); document.write( "
\n" ); document.write( "Multiplying we get:
\n" ); document.write( "

\n" ); document.write( "Next I'll isolate the cubed terms on the left side by subtracting all the non-cubed terms from both sides:
\n" ); document.write( "\"a%5E3+%2Bb%5E3+%2Bc%5E3+=+-3a%5E2b+-3ab%5E2+-+3a%5E2%2Ac-6abc-3b%5E2%2Ac+-+3ac%5E2-3bc%5E2\"
\n" ); document.write( "Factoring out -3 on the right side:
\n" ); document.write( "
\n" ); document.write( "Dividing both sides by abc. (We're told that a b and c are all non-zero so it is OK to divide by this.)
\n" ); document.write( "
\n" ); document.write( "Splitting up the fractions:
\n" ); document.write( "
\n" ); document.write( "Simplifying the fractions:
\n" ); document.write( "
\n" ); document.write( "(Note that the left side is the expression we hope is equal to 3.) Adding the like fractions on the right side:
\n" ); document.write( "
\n" ); document.write( "From a + b + c = 0:
  • Subtracting c from each side we get: a + b = -c
  • Subtracting b from each side we get: a + c = -b
  • Subtracting a from each side we get: b + c = -a
Substituting these expressions in for the numerators on the right side we get:
\n" ); document.write( "
\n" ); document.write( "Simplifying the fractions further:
\n" ); document.write( "\"a%5E2%2Fbc+%2Bb%5E2%2Fac+%2Bc%5E2%2Fab+=+-3%28-1+%2B+%28-1%29%2B+2%2B+%28-1%29%29\"
\n" ); document.write( "Simplifying:
\n" ); document.write( "\"a%5E2%2Fbc+%2Bb%5E2%2Fac+%2Bc%5E2%2Fab+=+-3%28-1%29\"
\n" ); document.write( "\"a%5E2%2Fbc+%2Bb%5E2%2Fac+%2Bc%5E2%2Fab+=+3\"
\n" ); document.write( "
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