1) a² - 2ab + b² = (a - b)²
2) a² - 12a + 36 = a² - 2 * a * 6 + 6² = (a - 6)²
3) 81 + 18y + y² = 9² + 2 * 9 * y + y² = (9 + y)²
1) a² - 2ab + b² = (a - b)²
2) a² - 12a + 36 = a² - 2 * a * 6 + 6² = (a - 6)²
3) 81 + 18y + y² = 9² + 2 * 9 * y + y² = (9 + y)²