Multiplication: the square of 6xy (the square of x-3xy)-the cube of 3xy (the square of 3xy).
=6x？ y？ - 18x？ y？ +(27x？ )? y？ ÷3x？ y？
=2x-6y+9x quartic y
(2) Factorization: the square of 64(x-y)-12 1(x+y).
=64(x-y)？ - 12 1(x+y)？
= 8x-8y- 1 1x- 1 1y
=-3x- 19y
(3) Simplify and re-evaluate: (a's square b-2ab's square -b's cube) ÷b-(a+b)(a-b) where a = half b =- 1.
(a？ b-2ab？ -B? )÷b-(a+b)(a-b)
=a？ -2ab-b？ -a？ +b？
=-2ab
Substitute a= 1/2 b=- 1 into -2ab:
-2ab=-2× 1/2×(- 1)
= 1
(5)| a+half |+(b-3)= 0 square, and find the value of the square of the algebraic formula (2a+b)+(2a+b)-6a0 ÷ 2b.
a=- 1/2 b=3
3ab-4ab+8ab-7ab+ab=______。
2.7x-(5x-5y)-y=______。
3.23 a3 BC 2- 15 ab2c+8 ABC-24 a3 BC 2-8 ABC = _ _ _ _ _ _。
4.-7x 2+6x+ 13 x2-4x-5x 2 = _ _ _ _ _ _。
5.2y+(-2y+5)-(3y+2)=______。
6.(2 x2-3xy+4 y2)+(x2+2xy-3 y2)= _ _ _ _ _ _。
7.2a-(3a-2 b+2)+(3a-4 b- 1)= _ _ _ _ _ _。
8.-6x2-7x2+ 15x2-2x2=______。
9.2x-(x+3y)-(-x-y)-(x-y)= _ _ _ _ _ _。
10.2 x+2y-[3x-2(x-y)]= _ _ _ _ _ _。
1 1.5-( 1-x)- 1-(x- 1)= _ _ _ _ _ _。
12.()+(4xy+7x2-y2)= 10x2-xy。
13.(4xy2-2x2y)-( )=x3-2x2y+4xy2+y3。
14. Given A=x3-2x2+x-4 and B=2x3-5x+3, calculate a+b = _ _ _ _.
15. Given A=x3-2x2+x-4 and B=2x3-5x+3, calculate a-b = _ _ _ _.
16. if a=-0.2 and b=0.5, the value of algebraic expression -(|a2b|-|ab2|) is _ _ _ _.
17. If a polynomial subtracts 3m4-m3-2m+5 to get -2m4-3m3-2m2- 1, then this polynomial is equal to _ _ _ _.
18.-(2 x2-y2)-[2 y2-(x2+2xy)]= _ _ _ _ _ _。
19. If -3a3b2 and 5ax- 1by+2 are similar terms, then x=______ _ _ _ _ _.
20.(-Y+6+3 Y4-Y3)-(2 y2-3 Y3+Y4-7)= _ _ _ _。 There are still some problems 1, 1, a+(2b-3c-4d) = _ _ _ _ _ _ _;
2、a-(-2 B- 3c+4d)= _ _ _ _ _ _ _ _；
3 、( m-n)-3(z-p)= _ _ _ _ _ _ _ _；
4、3x-[5x-(2x- 1)]= _ _ _ _ _ _ _ _；
5、4x 2-[6x-(5x-8)-x2]= _ _ _ _ _ _ _ _ _ _ _ _；
Two. Simplification (28 points)
1 、( 1 )( 3x+5y)+(5x-7y)-2(2x-4y)；
(2)5ab-{ 1、a+(2 B- 3c-4d)= 1
2、a-(-2 B- 3c+4d)= 1
3 、( m-n)-3(z-p)= 1
4、3x-[5x-(2x- 1)]=
5、4x2-[6x-(5x-8)-x2]=
6 、( 3x+5y)+(5x-7y)-2(2x-4y)；
7、5ab+[2a2b+(a2b-3ab)]-2a2b}
Three. Simplified evaluation (16)
(2x2-x-1)-(x2-x-)+3 (x2-1), where x= 1.
4. 1，7x-3y-4z =-(_ _ _ _ _ _ _)；
2、a2-2ab-a-b = a2-2ab-(_ _ _ _ _ _ _)；
3、5x 3-4x 2+2x-3 = 5x 3-(_ _ _ _ _ _)-3；
4、a3-a2b+ab2 =-(_ _ _ _ _ _ _)+ab2 = a3-(_ _ _ _ _ _ _)；
5、5a 2-6a+9b = 5a 2-3(_ _ _ _ _ _ _)=-6a-(_ _ _ _ _ _)；
6、x3-3x2y+3xy 2-y3 = x3-3x2y-(_ _ _ _ _ _)= x3-y3-(_ _ _ _ _ _)；
Verb (abbreviation of verb) (1) (x3-4x2y+5xy2-3y3)-(-2xy2-4x3+x2y);
(2) subtract 3a4-a3+2a- 1 from a polynomial to get 5a4+3a2-7a+2, and find this polynomial.
Six, simplify the following categories, and then evaluate (45 points)
(1) x-2(x- )+3( x+), where x =-4;
(2) (3xy-2x2)-(2x2-y2)-(y2-2xy)+(-y2+5x2+xy), where x =, y =-;
(3) 5xyz-{2x2y-[3xyz-(4xy2-x2y)]} where x =-2, y =- 1 and z = 3；; 7. It is known that m minus n equals 3, and the square of m minus the square of n equals 8. The answer to the last question of finding the value of MN; M^2-N^2=8
(M+N)(M-N)=8
M-N=3
M+N=8/3
2M=(3+8/3)= 17/3
M= 17/6
2N=(8/3-3)=- 1/3
N=- 1/6
MN=- 17/36
( 1)(x-y)？ -(x+y)(x-y)(2)[x(x？ y？ -xy)-y(x？ -x？ y)】÷3x？ y
Answer (1) The original formula = (x-y) (x-y-x-y) =-2xy+2y 2.
(2) The original formula = [X3Y2-X2y-X2y+X3Y2] ÷ 3x2y = 2/3xy-2/3.