If \( \Large a+b+c=14\ and\ a^{2}+b^{2}+c^{2}=96 \), then \( \Large \left(ab+bc+ca\right)=? \)
Correct Answer: Description for Correct answer:
We know that,
\( \Large \left(a+b+c\right)^{2}= \left(a^{2}+b^{2}+c^{2}\right)+2 \left(ab+bc+ca\right) \)
=>\( \Large 196=96+2 \left(ab+bc+ca\right) \)
=>\( \Large 2 \left(ab+bc+ca\right)=196-96=100 \)
Therefore, \( \Large \left(ab+bc+ca\right)=\frac{100}{2}=50 \)
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