(1)4a2-2ab+6ab-3b2 =4a2+4ab-3b2;
(2)原式=5x2(x2-1) =5x4-5x2;
(3)原式=(200-2)2 =2002-800+22 =40000-800+4 =39204;
(4)原式=8a3b4÷12a3b2 =b2;
(5)原式=[(-)÷]a7-2b5-5 =-a5;
(6)原式=(54×33-53×32+52×3)÷(5×3) =53×32-52×3+5 =1055;
(7)原式=3(y2-2yz+z2)-(4y2-z2) =3y2-6yz+3z2-4y2+z2 =-y2-yz+4z2;
(8)原式=(x3y2-x2y-x2y+x3y2)÷3x2y =(2x3y2-2x2y)÷3x2y =xy-. |