化简:(1)5x2-8x+5-3x2+6x;
1个回答

解题思路:(1)直接找出同类项,进而合并得出即可;

(2)首先去括号,进而找出同类项,合并同类项即可;

(3)首先去括号,进而找出同类项,合并同类项即可;

(4)首先去括号,进而找出同类项,合并同类项即可;

(5)首先去括号,进而找出同类项,合并同类项即可;

(6)首先去括号,进而找出同类项,合并同类项即可;

(7)首先去括号,进而找出同类项,合并同类项即可;

(8)首先去括号,进而找出同类项,合并同类项即可.

(1)5x2-8x+5-3x2+6x=2x2-2x+5;

(2)a3b+(a3b-2c)-2(a3b-c)

=a3b+a3b-2c-2a3b+2c,

=0;

(3)-3(2x2-xy)+4(x2-xy-6)

=-6x2+3xy+4x2-4xy-24

=-2x2-xy-24;

(4)2(2a2-9b)+3(-5a2-4b)-3b

=4a2-18b-15a2-12b-3b,

=-11a2-33b;

(5)(8a2-3ab-5b2)-(2a2-2ab+3b2

=8a2-3ab-5b2-2a2+2ab-3b2

=6a2-8b2-ab;

(6)-4xy+3([1/3]xy-2x)=-4xy+xy-6x=-3xy-6x;

(7)2a+2(a+1)-3(a-1)=2a+2a+2-3a+3=a+5;

(8)-3(2x2-xy)+4(x2+xy-6)=-6x2+xy+4x2+4xy-24=-2x2+5xy-24.

点评:

本题考点: 整式的加减.

考点点评: 此题主要考查了整式的加减运算,正确去括号后合并同类项是解题关键.