(1)原式=4x4y6•x3y3 =4x7y9;
(2)原式=[(2x+y)-1]2 =(2x+y)2-2(2x+y)•1+12 =4x2+4xy+y2-4x-2y+1;
(3)原式=(60-0.2)×(60+0.2) =602-0.22 =3600-0.04 =3599.96;
(4)原式=a3x4÷ax3-0.9ax3÷ax3 =2a2x-1.5;
(5)原式=7x2y3÷8x2y2-8x3y2z÷8x2y2 =y-xz;
(6)原式=1213÷(310×410×4) =1213÷(1210×4) =×123 =432;
(7)原式=4(x2+2x+1)-(4x2-25) =4x2+8x+4-4x2+25 =8x+29;
(8)原式=x2-2x-x2-2x =-4x. |