(2x-3y)+(5x+4y)
(8a-7b)-(4a-5b)
-(3x-2y+z)-[5x-(x-2y+z)-3x]
2(7x2+5x-3)-3(5x2-3x+2)
2b3+(3ab3-a2b)-2(ab2+b3)
(-6x2+5xy)-12xy-(2x2-9xy)
(x2-2x3+1)-(-1+2x3+2x2),其中x=2
3a-[-2b+(4a-3b)],其中a=-1,b=3
3ab-4ab+8ab-7ab+ab=
7x-(5x-5y)-y=
23a3bc2-15ab2c+8abc-24a3bc2-8abc=
-7x2+6x+13x2-4x-5x2=
2y+(-2y+5)-(3y+2)=
(2x2-3xy+4y2)+(x2+2xy-3y2)=
2a-(3a-2b+2)+(3a-4b-1)=
-6x2-7x2+15x2-2x2=
2x-(x+3y)-(-x-y)-(x-y)=
2x+2y-[3x-2(x-y)]=
5-(1-x)-1-(x-1)=
已知A=x3-2x2+x-4,B=2x3-5x+3,计算A+B=
若a=-0.2,b=0.5,代数式-(|a2b|-|ab2|)的值为
-(2x2-y2)-[2y2-(x2+2xy)]=
(-y+6+3y4-y3)-(2y2-3y3+y4-7)=
4x2-[7x2-5x-3(1-2x+x2)]=
3a-(2a-3b)+3(a-2b)-b=
x-[y-2x-(x+y)]=
3x-[y-(2x+y)]=
4a2n-an-(3an-2a2n)=
2x2y+3xy2-x2+2xy=
-5xm-xm-(-7xm)+(-3xm)=
当a=-1,b=-2时,
[a-(b-c)]-[-b-(-c-a)]=
当a=-1,b=1,c=-1时,
-[b-2(-5a)]-(-3b+5c)=
-2(3x+z)-(-6x)+(-5y+3z)=
-5an-an+1-(-7an+1)+(-3an)=
3a-(2a-4b-6c)+3(-2c+2b)=
9a2+[7a2-2a-(-a2+3a)]=
当2y-x=5时,5(x-2y)2-3(-x+2y)-100=