-
If a + 1 = b + 1 = c + 1 (where a ≠ b ≠ c), then abc is equal to b c a
-
- +1
- –1
- +1 and –1
- None of the options
Correct Option: C
| a + | = b + | = c + | = ±1 (let) | |||
| b | c | a |
| ⇒ a + | = 1 | |
| b |
⇒ ab + 1 = b ⇒ ab = b – 1
| b + | = 1 ⇒ | = 1 – b | ||
| c | c |
| c = | |
| 1 – b |
| ∴ abc = | = – 1 | |
| 1 – b |
| Again, a + | = – 1 | |
| b |
⇒ ab + 1 = –b ⇒ ab = –b – 1
| b + | = –1 ⇒ | = – 1 – b | ||
| c | c |
| c = | |
| – 1 – b |
∴ abc = 1
∴ abc = ±1
