If A2 + B2 + C2 = 250 and Ab + Bc + Ca = 3, Find a + B + C. - Mathematics

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Answer in Brief

If a2 + b2 + c2 = 250 and ab + bc + ca = 3, find a + b + c.

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Solution

Recall the formula

  `(a+b+c)^2 = a^2 +b^2 +c^2 + 2(ab + bc + ca)`

Given that

`a^2 + b^2 + c^2 = 250 , ab + bc + ca = 3 `

Then we have

`(a+b+c)^2 = a^2 + b^2 + c^2 + 2 (ab + bc+ca)`

`(a+b+c)^2 = 250 + 2.(3)`

`(a+b+c)^2 = 256`

 `(a+b+c)  =± 16`

  Is there an error in this question or solution?
Chapter 5: Factorisation of Algebraic Expressions - Exercise 5.5 [Page 24]

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RD Sharma Mathematics for Class 9
Chapter 5 Factorisation of Algebraic Expressions
Exercise 5.5 | Q 4 | Page 24

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