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A²+b²+c²=138 and ab +bc+ca=3, Find a+b+c


a ^(2) + b {}^(2) + c { = 138} and \: ab + bc + ca \: find \: a + b + c
ans pls?​

1 Answer

4 votes

Answer:

a + b + c = 12

Explanation:

The given information are;

a² + b² + c² = 138

a·b + b·c + c·a = 3

The required data = a + b + c

Using an online tool, we have;

(a + b + c)² = (a + b + c) × (a + b + c) = 2·a·b + 2·b·c + 2·c·a + a² + b² + c²

∴ (a + b + c)² = 2·(a·b + b·c + c·a) + (a² + b² + c²)

Where;

a·b + b·c + c·a = 3, and a² + b² + c² = 138, we have;

(a + b + c)² = 2 × 3 + 138 = 144

(a + b + c)² = 144

(a + b + c) = √144 = 12

a + b + c = 12.

User Derrin
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