1.-A* (-AB)^3
=-A(-A^3B^3)
=A^4B^3
2.(2X-3Y)^2-2(X-Y)(X+Y)
=4X^2-12XY+9Y^2-2X^2+2Y^2
=2X^2-12XY+11Y^2
3.[-(1\3)X^2Y][(3\4Y^2)-(1\2X)+1\3]
=[-(1\3)X^2Y](3\4Y^2)-[-(1\3)X^2Y](1\2X)+[-(1\3)X^2Y](1\3)
=-1\4X^2Y^3+1\6X^3Y-1\9X^2Y
4.方程组:2(A+B)=14 AB=10
A+B=14/2=7
A^2 B+A B^2
=AB(A+B)
=10×7
=70