Question

if a^2+b^2+c^2=250andab+bc+ca=3,thenfind a+b+c

Answer 1

by formula ,

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

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

(a + b + c)^2 = 250 + 2(3)
= 256
= 16^2

therefore: a + b + c = 16

Answer 2

Given that a^2 + b^2 + c^2 = 250 and ab + bc + ca = 3.a + b + c = ?

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

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

                     = 250 + 2(3)

                    = 256.


(a + b + c) = $\sqrt{256}$

(a + b + c) = 16.


Hope this helps!