9x² + 6x + 1 = (3x + 1)²
on utilise (a + b)²
x² - 14x + 49 = (x - 7)²
on utilise (a - b)²
1 + 12x + 36x² = (6x + 1)²
on utilise (a + b)²
x² - 64 = (x - 8)(x + 8)
on utilise (a - b)(a + b)
81 - x² = (9 - x)(9 + x)
on utilise (a - b)(a + b)
25x² - 36 = (5x - 6)(5x + 6)
on utilise (a - b)(a + b)
49x² - 4 = (7x - 2)(7x + 2)
on utilise (a - b)(a + b)
1 - 16x² = (1 - 8x)(1 + 8x)
on utilise (a - b)(a + b)
4x² - 9 = (4x - 9)(4x + 9)
on utilise (a - b)(a + b)
