1、16（a-b）²-9（a+b)²=[4（a-b)]²-[3(a+b)]²=(4a-4b)²-(3a+3b)²=[(4a-4b)+(3a+3b)][(4a-4b)-(3a+3b)]=(7a-b)(a-7b)2、x^5y-xy=xy(x^4-1)=xy(x^2^2-1)=xy(x^2+1)(x^2-1)=xy(x^2+1)(x...