1、(-1/2)^3÷(-1/2)^3×(-1/2)^3÷2^-3
=(-1/2)^3÷2^-3
=-1/8÷1/8
=-1
2、(2x^2)^3-3x^3(x^3+2x^2+x)
=8x^6-3x^6-6x^5-3x^4
=5x^6-6x^5-3x^4
3、2(x^2-3xy-2y^2)-3(4-3x-2x^2)
=2x^2-6xy-4y^2-12+9x+6x^2
=8x^2-6xy-4y^2+9x-12
4、(2/3)^2002×(1.5)^2001×(-1)^2003
=-(2/3)^2002×(1.5)^2001
=-(2/3x1.5)^2001×2/3
=-1^2001x2/3
=-2/3
5、8^n×(1/8)^n+1(n∈N)
=8^(n-n-1)
=8^-1
=1/8
6、(x+y)(x-y)-(x+2y)^2
=x^2-y^2+x^2+4xy+4y^2
=2x^2+4xy+3y^2
7、(2a+b)^2-(2a+b)(2a-b)
=4a^2+4ab+b^2-4a^2+b^2
=4ab+2b^2
8、(2x-y)^2-(4x+y)(y-4x)
=4x^2-4xy+y^2-16x^2+y^2
=-12x^2-4xy+2y^2