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If a+b+c=9 and a b+b c+c a=40 , find a^2...

If `a+b+c=9` and `a b+b c+c a=40 ,` find `a^2+b^2+c^2dot`

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`(a + b + c)² = a² + b² + c² + 2(ab + bc + ca)`
`(9)² = a² + b² + c²+2. (40)`
`a² + + b² + c² + 80 = 81`
`a^2 + b^2 + c^2 = 81 - 80`
`a²+ b²+ c² = 1'`
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RD SHARMA-ALGEBRAIC IDENTITIES-All Questions
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  2. Prove that a^2+b^2+c^2-a b-b c-c a is always non-negative for all valu...

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  3. If a+b+c=9 and a b+b c+c a=40 , find a^2+b^2+c^2dot

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  4. Simplify : (a+b+c)^2

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  7. If a-b=6 and a b=20 , find the value of a^3-b^3

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  8. If a+b=10 and a b=21 , find the value of a^3+b^3

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  9. If 4x^2+y^2=40 and x y=6, find the value of 2x+ydot

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  10. If a+b=7 and a b=12 , find the value of (a^2-a b+b^2)

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  11. If x^2+1/(x^2)=83. find the value of x^3-1//x^3

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  14. If a+b+c=15 and a^2+b^2+c^2=83 , find the value of a^3+b^3+c^3-3abc

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  15. Without actually calculating the cubes. Find the value of each of t...

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  16. Ifa +b+c=9 and a^2+b^2+c^2=35 , find the value of a^3+b^3+c^3-3a b c

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