a² + 2a + 1 = a² + 2 * a * 1 + 1² = (a + 1)²
а² + 2а + 1 = 0 D = 4-4 = 0
a₁₂ = -2 : 2 = -1
a² + 2a + 1 = (a + 1)(a + 1) = (a + 1)²
a² + 2a + 1 = a² + 2 * a * 1 + 1² = (a + 1)²
а² + 2а + 1 = 0 D = 4-4 = 0
a₁₂ = -2 : 2 = -1
a² + 2a + 1 = (a + 1)(a + 1) = (a + 1)²