.-1的立方根+（-1）的三次方的立方根+（-1）²的立方根
=-1+(-1)+1
=-1
2.（2x+3y-1）（1+2x-3y）
=[2x+(3y-1)][2x-(3y-1)]
=4x^2-(3y-1)^2
=4x^2-9y^2+6y-1