合并同类项(1)3b^2-(a^2+b^2)-b^2(2)x+(2x-1)-(x/3 +3)(3)-2(ab-3a^2)+(5ab-a^2)(4)2a^2- 1/2 (ab+a^2)-8ab(5)-(b-4)+4(-b-3)(6)1/2 (x^2-y)+1/3 (x-y^2)+1/6 (x^2+y^2)

(1)3b^2-(a^2+b^2)-b^2
=3b^2-a^2-b^2-b^2
=b^2-a^2
(2)x+(2x-1)-(x/3 +3)
=x+2x-1-x/3-3
=8x/3-4
(3)-2(ab-3a^2)+(5ab-a^2)
=-2ab+6a^2+5ab-a^2
=5a^2+3ab
(4)2a^2- 1/2 (ab+a^2)-8ab
=2a^2-ab/2-a^2/2-8ab
=3a^2/2-17ab/2
(5)-(b-4)+4(-b-3)
=-b+4-4b-12
=-5b-8
(6)1/2 (x^2-y)+1/3 (x-y^2)+1/6 (x^2+y^2)
=x^2/2-y/2+x/3-y^2/3+x^2/6+y^2/6
=2x^2/3-y^2/6-y/2+x/3

(1)3b^2-(a^2+b^2)-b^2
=3b^2-a^2-b^2-b^2
=b^2-a^2
(2)x+(2x-1)-(x/3 +3)
=(x+2x-x/3)+(-1-3)
=(8/3)x-4
(3)-2(ab-3a^2)+(5ab-a^2)
=-2ab+6a^2+5ab-a^2
=3ab+5a^2
(4)2a^2- 1/2 (ab+a^2)-8ab
=2a^2-1/2ab-1/2a^2-8ab
=(3/2)a^2-(17/2)ab
(5)-(b-4)+4(-b-3)
=-b+4-4b-12
=-5b-8
(6)1/2 (x^2-y)+1/3 (x-y^2)+1/6 (x^2+y^2)
=1/2x^2-1/2y+1/3x-1/3y^2+1/6x^2+1/6y^2
=(1/2x^2+1/6x^2)+(-1/3y^2+1/6y^2)-1/2y+1/3x
=2/3x^2-1/6y^2-1/2y+1/3x