Respuesta :

Answer:

ix) (2a + 3)² = 4a² +12a + 9

x) a) x² + 7x + 12 = (-3)² + 7(-3) + 12 = 9 -21 + 12 = 0

b) x² - 5x + 6 = (-3)² - 5(-3) + 6 = 9 + 15 + 6  = 30

c) x² + 5x = (-3)² + 5(-3) = 9 -15 =  -6