(1) x平方-6x+9 -36 =(x-3)平方-36 =(x-3+6)(x-3-6) =(x+3)(x-9)(2)a平方+3a+9/4 -121/4=(a+3/2)平方-121/4=(a+3/2+11/2)(a+3/2-11/2)=(a+7)(a-4)
(x-9)(x+3)和(x+7)(x-4)
啊