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If a2 + b2 + 2b + 4a + 5 = 0, then the value of a − b is a + b
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- 3
- –3
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1 3 -
− 1 3
Correct Option: C
a2 + b2 + 2b + 4a + 5 = 0
⇒ a2 + 4a + b2 + 2b + 5 = 0
⇒ a2 + 4a + 4 + b2 + 2b + 1 = 0
⇒ (a + 2)2 + (b + 1)2 = 0
It is possible only when
a + 2 = 0 ⇒ a = –2
and, b + 1 = 0 ⇒ b = – 1
| ∴ | = | ||
| a + b | −2 − 1 |
| = | = | ||
| −3 | 3 |
