-（3a^2-4)-(a^2-3a+5)+（4a-a^2)
=-3a^2+4-a^2+3a-5+4a-a^2
=(-3-1-1)a^2+(3+4)a+4-5
=-5a^2+7a-1
=-5*25-7*5-1
=-161
4x^2y-((6xy-2(4xy-1)-x^2y))+1
=5x^2y+2xy-3
=xy(5x+2)-3
=-1/2*(-5/2+2)-3
=-11/4