Question

if a+b+c=12and a^2+b^2+c^2=66 then find the value of ab+bc+ca​

Answer 1

(a + b + c)² = a² + b² + c² + ab + bc + ca

=> 12² = 66 + ab + bc + ca

=> 144 = 66 + ab + bc + ca

=> 144 - 66 = ab + bc + ca

=> 78 = ab + bc + ca

.°. ab + bc + ca = 78

Answer 2

Step-by-step explanation:

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