3ab-4ab+8ab-7ab+ab
23a3bc2-15ab2c+8abc-24a3bc2-8abc
2y+(-2y+5)-(3y+2)
(2x2-3xy+4y2)+(x2+2xy-3y2)
2a-(3a-2b+2)+(3a-4b-1)
2x-(x+3y)-(-x-y)-(x-y)
2x+2y-[3x-2(x-y)]
5-(1-x)-1-(x-1)
(4xy2-2x2y)-( )=x3-2x2y+4xy2+y3.
3x-2x2+x-4+2x3-5x+3
3x-2x+x-4-(2x3-5x+3)
-(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-(3x2y+2x2-3xy-4)
-5xm-xm-(-7xm)+(-3xm)
[a-(b-c)]-[-b-(-c-a)] 当a=-1,b=-2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)]
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)=______.
( )+(4xy+7x2-y2)=10x2-xy.
(4xy2-2x2y)-( )=x3-2x2y+4xy2+y3.
已知A=x3-2x2+x-4,B=2x3-5x+3,计算A+B=______.
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______.
一个多项式减去3m4-m3-2m+5得-2m4-3m3-2m2-1,那么这个多项式等于______.
-(2x2-y2)-[2y2-(x2+2xy)]=______.
若-3a3b2与5ax-1by+2是同类项,则x=______,y=______.
(-y+6+3y4-y3)-(2y2-3y3+y4-7)=______.
化简代数式4x2-[7x2-5x-3(1-2x+x2)]的结果是______.
2a-b2+c-d3=2a+( )-d3=2a-d3-( )=c-( ).
3a-(2a-3b)+3(a-2b)-b=______.
化简代数式x-[y-2x-(x+y)]等于______.
[5a2+( )a-7]+[( )a2-4a+( )]=a2+2a+1.
3x-[y-(2x+y)]=______.
化简|1-x+y|-|x-y|(其中x<0,y>0)等于______.
已知x≤y,x+y-|x-y|=______.
已知x<0,y<0,化简|x+y|-|5-x-y|=______.
4a2n-an-(3an-2a2n)=______.
若一个多项式加上-3x2y+2x2-3xy-4得
2x2y+3xy2-x2+2xy,
则这个多项式为______.
5xm-xm-(-7xm)+(-3xm)=______.
当a=-1,b=-2时,
[a-(b-c)]-[-b-(-c-a)]=______.
43.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=______.
当2y-x=5时,5(x-2y)2-3(-x+2y)-100 =
对不起,只找到和并同类项 3ab-4ab+8ab-7ab+ab
23a3bc2-15ab2c+8abc-24a3bc2-8abc
2y+(-2y+5)-(3y+2)
(2x2-3xy+4y2)+(x2+2xy-3y2)
2a-(3a-2b+2)+(3a-4b-1)
2x-(x+3y)-(-x-y)-(x-y)
2x+2y-[3x-2(x-y)]
5-(1-x)-1-(x-1)
(4xy2-2x2y)-( )=x3-2x2y+4xy2+y3.
3x-2x2+x-4+2x3-5x+3
1.已知4xⁿy²与bx³y²的和是0,求-ab-2+3ab-5ab+3的值。
这道题没有办法做,如果n是a的话还可以做,如下
根据你的前提条件,这是同类项的题,而且4xⁿy²与bx³y²的和是0,那就合并同类项,所以n=3,b=-4,结果37。
2.如果关于代数式5x²+mx+nx²-x+6的值与x的值无关,求m-n的值。
同理做第二题,现合并同类项,即上式等于(5+n)x²+(m-1)x+6,已知与x的值无关,可得,5+n=0,m-1=0,结果得6
3.已知│x-2│与3y²互为相反数,求代数式⅔x-y+⅓x-9y。
由珐讥粹客诔九达循惮末已知可得│x-2│+3y²=0,一看这两个都是非负数的,可得x-2=0,y=0
代数式结果:2
解原式=一x^2+2X—3X+2X^2
=一X^2+2X^2+2X—3X
=X^2一X,1,原式=-x^2+2x-3x+2x^2=x^2-x
在拆括号的时候,要注意括号前面的符号,如果是“+”,括号内的符号就不变:若是“-”,括号内的符号则全部相反。,2,原式=-x²+2x-3x+2x²=x²-x=x(x-1),1,-(x²-2x)+(-3x+2x²)
=-x²+2x-3x+2x²
=x²-x,0,
例1、合并同类项 (1)(3x-5y)-(6x+7y)+(9x-2y) (2)2a-[3b-5a-(3a-5b)] (3)(6m2n-5mn2)-6(m2n-mn2) (1)(3x-5y)-(6x+7y)+(9x-2y) =3x-5y-6x-7y+9x-2y (正确去掉括号) =(3-6+9)x+(-5-7-2)y (合并同类项) =6x...
3ab-4ab+8ab-7ab+ab
23a3bc2-15ab2c+8abc-24a3bc2-8abc
2y+(-2y+5)-(3y+2)
(2x2-3xy+4y2)+(x2+2xy-3y2)
2a-(3a-2b+2)+(3a-4b-1)
2x-(x+3y)-(-x-y)-(x-y)
2x+2y-[3x-2(x-y)]
5-(1-x)-1-(x-1)
(4xy2-2x2y)-( )=x3-2x2y+4xy2+y3.
3x-2x2+x-4+2x3-5x+3
3x-2x+x-4-(2x3-5x+3)
-(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-(3x2y+2x2-3xy-4)
-5xm-xm-(-7xm)+(-3xm)
[a-(b-c)]-[-b-(-c-a)] 当a=-1,b=-2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)]
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)=______.
( )+(4xy+7x2-y2)=10x2-xy.
(4xy2-2x2y)-( )=x3-2x2y+4xy2+y3.
已知A=x3-2x2+x-4,B=2x3-5x+3,计算A+B=______.
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______.
一个多项式减去3m4-m3-2m+5得-2m4-3m3-2m2-1,那么这个多项式等于______.
-(2x2-y2)-[2y2-(x2+2xy)]=______.
若-3a3b2与5ax-1by+2是同类项,则x=______,y=______.
(-y+6+3y4-y3)-(2y2-3y3+y4-7)=______.
化简代数式4x2-[7x2-5x-3(1-2x+x2)]的结果是______.
2a-b2+c-d3=2a+( )-d3=2a-d3-( )=c-( ).
3a-(2a-3b)+3(a-2b)-b=______.
化简代数式x-[y-2x-(x+y)]等于______.
[5a2+( )a-7]+[( )a2-4a+( )]=a2+2a+1.
3x-[y-(2x+y)]=______.
化简|1-x+y|-|x-y|(其中x<0,y>0)等于______.
已知x≤y,x+y-|x-y|=______.
已知x<0,y<0,化简|x+y|-|5-x-y|=______.
4a2n-an-(3an-2a2n)=______.
若一个多项式加上-3x2y+2x2-3xy-4得
2x2y+3xy2-x2+2xy,
则这个多项式为______.
5xm-xm-(-7xm)+(-3xm)=______.
当a=-1,b=-2时,
[a-(b-c)]-[-b-(-c-a)]=______.
43.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=______.
当2y-x=5时,5(x-2y)2-3(-x+2y)-100 =
对不起,只找到和并同类项 3ab-4ab+8ab-7ab+ab
23a3bc2-15ab2c+8abc-24a3bc2-8abc
2y+(-2y+5)-(3y+2)
(2x2-3xy+4y2)+(x2+2xy-3y2)
2a-(3a-2b+2)+(3a-4b-1)
2x-(x+3y)-(-x-y)-(x-y)
2x+2y-[3x-2(x-y)]
5-(1-x)-1-(x-1)
(4xy2-2x2y)-( )=x3-2x2y+4xy2+y3.
3x-2x2+x-4+2x3-5x+3
1.已知4xⁿy²与bx³y²的和是0,求-ab-2+3ab-5ab+3的值。
这道题没有办法做,如果n是a的话还可以做,如下
根据你的前提条件,这是同类项的题,而且4xⁿy²与bx³y²的和是0,那就合并同类项,所以n=3,b=-4,结果37。
2.如果关于代数式5x²+mx+nx²-x+6的值与x的值无关,求m-n的值。
同理做第二题,现合并同类项,即上式等于(5+n)x²+(m-1)x+6,已知与x的值无关,可得,5+n=0,m-1=0,结果得6
3.已知│x-2│与3y²互为相反数,求代数式⅔x-y+⅓x-9y。
由珐讥粹客诔九达循惮末已知可得│x-2│+3y²=0,一看这两个都是非负数的,可得x-2=0,y=0
代数式结果:2
解原式=一x^2+2X—3X+2X^2
=一X^2+2X^2+2X—3X
=X^2一X,1,原式=-x^2+2x-3x+2x^2=x^2-x
在拆括号的时候,要注意括号前面的符号,如果是“+”,括号内的符号就不变:若是“-”,括号内的符号则全部相反。,2,原式=-x²+2x-3x+2x²=x²-x=x(x-1),1,-(x²-2x)+(-3x+2x²)
=-x²+2x-3x+2x²
=x²-x,0,
例1、合并同类项 (1)(3x-5y)-(6x+7y)+(9x-2y) (2)2a-[3b-5a-(3a-5b)] (3)(6m2n-5mn2)-6(m2n-mn2) (1)(3x-5y)-(6x+7y)+(9x-2y) =3x-5y-6x-7y+9x-2y (正确去掉括号) =(3-6+9)x+(-5-7-2)y (合并同类项) =6x...