Question

Answer the following question:-

Answer 1

Hello Friend.

Here is your answer below,

Given values are,

a^2+b^2+c^2 = 90. and a+b+c = 20

Now going to solution.

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

(20)^2 = 90 + 2( ab + bc + ca )

400 = 90 + 2(ab + bc + ca )

400 - 90 = 2(ab + bc + ca )

310 = 2( ab + bc + ca )

310/2 = ab + bc + ca

155 = ab + bc + ca

so that (ab + bc + ca = 155) Answer.

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Answer 2

Answer:

155 is the correct answer

if you want explaination

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