Artur z miasta Neptuna:
3a
2 −4ab+b
2 = −a
2 + (4a
2 − 4ab+b
2) = −a
2 + (2a−b)
2 = ((2a−b) −a)((2a−b) +a) =
(a−b)(3a−b)
3a
2 + 2ab − b
2 = −(−4a
2 + a
2 − 2ab + b
2) = 4a
2 − (a−b)
2 = (2a − (a−b))(2a+(a−b)) =
(a+b)(3a−b)
więc:
| | (a−b)(3a−b) | | a−b | |
... = |
| = |
| |
| | (a+b)(3a−b) | | a+b | |
