Question

If a + b + c = 5, a² + b²+ c² = 29, then find the value of ab + bc + ca.​

Answer 1

Step-by-step explanation:

(a³+b³+c³)=3abc

(a+b+c)(a²+b²+c²-ab-bc-cd)

5(29)-(ab+bc+ca)=0

ab+bc+ca=145

Answer 2

(a+b+c)²=25

a²+b²+c²+2(ab+bc+ca)=25

ab + bc + ca.= -2 [putting the value]

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