Разложите многочлен на множители. 100a^2 - (5a + 9)^2
100a^2-(5a+9)^2 100a^2-(25a^2+90a+81) 100a^2-25a^2-90a-81 75a^2-90a-81
100a^2-25a^2-90a-81=75a^2-90a-81