1) (y-4)² = (y-4)(y-4) = y² - 4y - 4y + 16 = y² - 8y + 16
2) (7x+a)² = (7x+a)(7x+a) = 49x² + 7ax + 7ax + a² = 49x² + 14ax + a²
1) (y-4)² = (y-4)(y-4) = y² - 4y - 4y + 16 = y² - 8y + 16
2) (7x+a)² = (7x+a)(7x+a) = 49x² + 7ax + 7ax + a² = 49x² + 14ax + a²