(X-1)²-49
=(x-1+7)(x-1-7)
=(x+6)(x-8)
9(a-b)²-30(a-b)+25
=[3(a-b)-5]²
=(3a-3b-5)²
x的四次方-16y的四次方
=(x²-4y²)(x²+4y²)
=(x+2y)(x-2y)(x²+4y²)
(a+b)²-9(a-b)平方
=(a+b+3(a-b))(a+b-3(a-b))
=(4a-2b)(-2a+4b)
=4(2a-b)(2b-a)
(X-1)²-49
=(x-1+7)(x-1-7)
=(x+6)(x-8)
9(a-b)²-30(a-b)+25
=[3(a-b)-5]²
=(3a-3b-5)²
x的四次方-16y的四次方
=(x²-4y²)(x²+4y²)
=(x+2y)(x-2y)(x²+4y²)
(a+b)²-9(a-b)平方
=(a+b+3(a-b))(a+b-3(a-b))
=(4a-2b)(-2a+4b)
=4(2a-b)(2b-a)