求使N的三次方加100能被

按字母x、y进行同类项合并,可得：mx^3+3nxy^2+2x^3-xy^2+y=(m+2)x^3+(3n-1)xy^2+y,要使它不含三次项,则三次项(m+2)x^3和(3n-1)xy^2的系数都为

m^2=n+2n^2=m+2相减：m^2-n^2=n-m(m-n)(n+m)=n-m当m≠n时,m+n=-1m^3+n^3-2mn=m*m^2+n*n^2-2mn=m(n+2)+n(m+2)-2mn=

设n^3+100=k(n+10)因为n为正整数,所以k为正整数(n^3+100)/(n+10)=k(n^3+1000)/(n+10)-900/(n+10)=k(n^2-10n+100)-900/(n+

mx³-3nxy²+2x³-xy²+y不含三次项m+2=0m=-2-3n-1=0n=-1/32m+3n=-4-1=-5

2^(2n+3)-2^(2n+1)=192,（疑似输入错误,今作了改动）2^[(2n+1)+2]-2^(2n+1)=192,2^2*2^(2n+1)-2^(2n+1)=192,4*2^(2n+1)-2

1^3+2^3+.+n^3=n^2(n+1)^2/4=[n(n+1)/2]^2(n+1)^4-n^4=[(n+1)^2+n^2][(n+1)^2-n^2]=(2n^2+2n+1)(2n+1)=4n^3

是求a的m+n次方吧?a^m=4a^n=3a^(m+n)=a^m*a^n=4*3=12如果是a的n加3次方a^m=4a^n=3a^(n+3)=a^n*a^3=3a^3

先分解因式,后乘法.(X^4-Y^4)/(X^3+X^2Y+XY^2+Y^3)=(X-Y)(X+Y)(X^2+Y^2)/(X^3+X^2Y+XY^2+Y^3)=(X-Y)(X^3+X^2Y+XY^2+

n^2+n-1=0可得：n^2+n=1n^3+2n^2+2009=n^3+n^2+n^2+2009=n(n^2+n)+n^2+2009=n+n^2+2009=1+2009=2010

7x^3-6x^3y+3x^2y+3x^3+6x^3y-3x^2y-10x^3,其中x=-2010.y=2012=(7x^3+3x^3-10x^3)+(6x^3y-6x^3y)+(3x^2y-3x^2

25502500加到n的立方的话结果就是[1/2*n*(n+1)]平方

因为　x^3+ax^2+1能被x--1整除　　所以　可设x^3+ax^2+1=(x^2+Mx--1)(x--1)=x^3+Mx^2--x--x^2--Mx+1=x^3+(M--1)x^2+(--M--

因为一个数的3次,奇数的仍然是奇数,偶数的仍然是偶数,减去本身就是偶数又因为3N+1）^2=9M^2+1+6M,3M+2)^2=9M^2+3+1+12M所以会N^3会是6X+N,所以N的三次方-N能被

因为m^2=n+4,n^2=m+4所以m^2-n^2=（n+4）-(m+4)=n-m即(m-n)(m+n)=-(m-n)m+n=-1m^3-2mn+n^3=m·m^2-2mn+n·n^2=m(n+2)

√（60^3+80^3+100^3)=√((60+80)(60^2+80^2-80*60)+100^3)=√(140*(100^2-4800)+100^3)=√((140*5200)+100^3)=√

Sin3x=3sinx-4(sinx的三次方)因此sinx的三次方=3/4sinx-1/4sin3xN阶导数为3/4sin(x+n*π/2)-3的N次方/4sin(3x+n*π/2)

n^3+5n=n(n^2+5)n与(n^2+5)奇偶性互反,n=3k,3k+1,3k+2,原式也都可被3整除再问：n^3+5n=n(n^2-1+6)=(n-1)n(n+1)+6n

m³n³-1/2mn²＋n²-2m³n³＋0.5mn²＋n²＋m³n³-2n²-3=m&s

再问：最后方程组的那个我看不懂为什么啊我是自学的求教再答：同次幂的系数相等

n^3+5n=n^3-n+6n=n(n-1)(n+1)+6nn(n-1)(n+1)为三个连续自然数的积,能被2及3整除,因此能被6整除6n能被6整除.因此上式能被6整除.