整式的乘法计算题20题要有答案和过程,急啊!跪求!
1个回答

1,(m+2)(m2+4)(m+2)

=(m+2) (m+2) (m2+4)

=( m2+4m+4) (m2+4)

=(m2+4) (m2+4)+4m(m2+4)

=m4+8m+16+4m3+16m

2,20022-2001*2003

=(2001+1)(2003-1)-2001*2003

=2001*2003+2001+2003+1-2001*2003

=2001+2003+1

3,(x-5)(x+5)-(x+1)(x+5)

=x2-25-(x2+6x+5)

=-6x-30

4,(-a+2b的平方)-(a+2b)(2b-a)

=(2b-a) (2b-a)-(2b+a)(2b-a)

=4b2-4ab+a2-4b2+a2

=2 a2-4ab 5..(X-1/2y)-(X+Y)(X+1/4y)

=X-XY+1/4Y-X-1/4XY-XY-1/4Y

=-9/4XY

6.a的四次方-(1-a)(1+a)(1+a)

=a的四次方-(1-a)(1+a)

=a的四次方-1+a的四次方

=2a的四次方-1 7.已知x^n=2,y^n=3,求(xy)^2n的值 因为(xy)^2n = x^4n*y^2n

所以(xy)^2n = (x^n*x^n*x^n*x^n)(y^n*y^n)

(也就是分解成4个x^n乘2个y^n)

把x^n=2,y^n=3代入,

原式=(4*2)(3*2)

=48 8.试说明(5^2*3^2n+1)-(2^2*3^2n+2)是13 的倍数(5^2*3^2n+1)-(2^2*3^2n+2)

=25*3^(2n+1)-4*3*3^(2n+1)

=3^(2n+1)*(25-12)

=13*3^(2n+1)

所以(5^2*3^2n+1)-(2^2*3^2n+2)是13 的倍数9.若2x+y=0,求4x^3 +2xy(x+y)+y^3

4x^3 +2xy(x+y)+y^3

=4x^2+2x^2y+2xy^2+y^3

=4x^2(2x+y)+y^2(2x+y)

=(2x+y)(4x^2+y^2)

=0

10.若m^2 +m-1=0,求m^3 +2m^2+2008的值 m^2 +m-1=0

m^2 +m=1

m^3 +2m^2+2008

=(m^3+m^2)+m^2+2008

=m(m^2+m)+m^2+2008

=m^2+m+2008

=1+2008

=2009 11.(a-1)(1+a^2)(1+a)(1-2a)^2(2a+1)^2

=(a^2-1)(1+a^2)(1-4a^2)^2

=(a^4-1)(1-8a^2+16a^4)

=a^4-8a^6+16a^8-1+8a^2-16a^4

=16a^8-8a^6-15a^4+8a^2-1

12.(a+1)^2(a^2-2a+1)-(a-2)^2(a^+4a+4)

=(a+1)^2(a-1)^2-(a-2)^2(a+2)^2

=(a^2-1)^2-(a^2-4)^2

=(a^2-1+a^2-4)(a^2-1-a^2+4)

=(2a^2-5)*3

=6a^2-15 13.(1-1/4)(1-1/9)(1-1/16)……(1-1/100)要过程(1-1/4)=(1+1/2)(1-1/2)=3/2*1/2

(1-1/9)=(1+1/3)(1-1/3)=4/3*2/3

……

(1-1/100)=(1+1/10)(1-1/10)=11/10*9/10

(1-1/4)(1-1/9)(1-1/16)…… (1-1/81)(1-1/100)

=1/2*3/2*2/3*4/3……9/10*11/10

=11/20 14.(x-5)(x+5)-(x+1)(x+5)

=.=(x+5)(x-5-x+1)=-4x-20

15.已知a^2+4a+(a+b)^2+10(a+b)+29=0

求:3a^2-〖a^2b-(3ab-a^2b)-4a^〗-2ab的值

、(a+2)^2+(a+b+5)^2=0

∵非负的数相加等于零,只原式有可能是均为0

∴a+2=0且a+b+5=0

∴a=-2,b=-3

合并同类项,得

原式=7a^2-2a^2b+ab=58 16.x^2+mx-15=(x+3)(x+n)

x^2+mx-15=x^2+(n+3)x+3n

由对应系数相等,可得

m=n+3

-15=3n

解得m=-2,n=-5

17.4^m·8^(m+1)÷2^m的值为8192,则M的值全部化为2的指数函数

原式=2^(2m)*2^(3m+3)/2^m=2^(4m+3)

又∵8192=2^13

∴4m+3=13,

解得m=2.5 18.甲、乙两人共同计算一道整式乘法:(2x+a)(3x+b) 由于甲抄错了第一个多项式中a的符号,得到的结果为6(x的平方)+11x-10,由于乙漏抄 了第二个多项式中x的系数,得到的结果为2(X的平方)-9x+10.(1)你能否知道式子中a、b的值各是多少?(2)请你算出这道整式乘法的正确结果.甲:(2x-a)(3x+b)=6x^2+(2b-3a)x-ab=6x^2+11x-10

乙:(2x+a)(x+b)=2x^2+(2b+a)x+ab=2x^2-9x+10

所以:2b-3a=11

a+2b=-9

a=-5,b=-2

(2)正确的是:(2x-5)(3x-2)=6x^2-(4+15)x+10=6x^2-19x+10 19(2a+1/2b)(2a-1/2b)

=[(2a+1/2b)*(2a-1/2b)]

=[(2a)^2-(1/2b)^2]

=(4a^2-1/4b^2)

=16a^4-2a^2b^2+1/16b^4

20.6(7+1)(7+1)(7四次方+1)-(7八次方+1)+1

=(7-1)(7+1)(7+1)(7四次方+1)-(7八次方+1)+1

=(7-1)(7+1)(7四次方+1)-(7八次方+1)+1

=(7四次方-1)(7四次方+1)-(7八次方+1)+1

=7八次方-1-(7八次方+1)+1

=-1 21.(2x^2-x-1)^3=ax^6+bx^5+cx^4+dx^3+ex^2+fx+g 求a+c+e令x=1:(2-1-1)^3=0=a+b+c+d+e+f+g.[1]

令x=0:

(0-0-1)^3=-1=g

令x=-1:(2+1-1)^3=8=a-b+c-d+e-f+g.[2]

[1]+[2]:2a+2c+2e+2g=8

a+c+e-1=4

a+c+e=5 22.899×901+1

=(900-1)*(900+1)+1

=900^2-1+1

=900^2

=810000

23.123^2-124×122

=123^2-(123+1)*(123-1)

=123^2-(123^2-1)

=123^2-123^2+1

=1 24.比较2的333次方与3的222次方的大小

2^333=8^111

3^222=9^111

所以 2^333