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If a + b + c = 5, ab + bc + ca = 7 and abc = 3, find the value of
a + b 
+ b + c + c + a b a c b a c
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8 2 3 -
7 2 3 -
9 2 3 -
8 1 3
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Correct Option: A
a + b + c = 5;
ab + bc + ca = 7
abc = 3
a² + b² + c² = (a + b + c)² – 2 (ab + bc + ca)
= 25 – 2 × 7 = 11.
Clearly,
a = b = 1, c = 3
a = c = 1, b = 3
b = c = 1, a = 3
| ∴ | | + | | + | | + | | + | | + | | ||||||
| b | a | c | b | a | c |
| = (1 + 1) + | | + 3 | | + | | 3 + | | ||
| 3 | 3 |
| = 8 + | + | = 8 | |||
| 3 | 3 | 3 |
