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If a+b+c=9anda^(2)+b^(2)+c^(2)=21, then ...

If `a+b+c=9anda^(2)+b^(2)+c^(2)=21`, then `ab+bc+ca` is equal to

A

30

B

15

C

51

D

60

Text Solution

Verified by Experts

The correct Answer is:
A
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