(1)先閲讀,再填空:(x+5)(x+6)=x2+11x+30; (x-5)(x-6)=x2-11x+30;...
問題詳情:(1)先閲讀,再填空:(x+5)(x+6)=x2+11x+30; (x-5)(x-6)=x2-11x+30;(x-5)(x+6)=x2+x-30; (x+5)(x-6)=x2-x-30.觀察上面的算式,根據規律,直接寫出下列各式的結果:(a+90)(a-100)=____________; (y-80)(y-90)=____________.(2)先閲讀...