計(jì)算:
(1)23×22=______;
(2)(3×2)2=______;
(3)(23)2=______;
(4)a7÷a3=______
(5)3x4•4x3=______;
(6)-3xy(2x-3y)=______.
(7)(x-2)(x+2)=______;
(8)(1-2x)2=______.
解:(1)23×22=32;
(2)(3×2)2=36;
(3)(23)2=64;
(4)a7÷a3=a4;
(5)3x4•4x3=12x7;
(6)-3xy(2x-3y)=-6x2y+9xy2;
(7)(x+2)(x-2)=x2-4;
(8)(1-2x)2=1-4x+4x2.
故答案為32;36;64;a4;12x7;-6x2y+9xy2;x2-4;1-4x+4x2.
分析:(1)利用同底數(shù)冪的法則計(jì)算;
(2)先算括號(hào)里的乘法,再算乘方;
(3)根據(jù)冪的乘方法則計(jì)算;
(4)根據(jù)同底數(shù)冪的除法法則計(jì)算;
(5)根據(jù)單項(xiàng)式乘以單項(xiàng)式的法則計(jì)算;
(6)根據(jù)單項(xiàng)式乘以多項(xiàng)式的法則計(jì)算;
(7)根據(jù)平方差公式計(jì)算;
(8)根據(jù)完全平方差公式展開計(jì)算.
點(diǎn)評(píng):本題考查了整式的混合運(yùn)算,解題的關(guān)鍵是注意運(yùn)算法則的使用.