1.已知:x^2+mx+n乘以x+2得到的积为x^3+2x+12,求m,n2.2^2009*5^2011的积有多少个0?是几位数?3.有理数x,y,z满足|x-y-2|+(3x-6y-7)^2+|3y+3z-4|=0,求x^3n y^3n+1 z^4n-x的值 (n是正整数) 求x,y,
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![1.已知:x^2+mx+n乘以x+2得到的积为x^3+2x+12,求m,n2.2^2009*5^2011的积有多少个0?是几位数?3.有理数x,y,z满足|x-y-2|+(3x-6y-7)^2+|3y+3z-4|=0,求x^3n y^3n+1 z^4n-x的值 (n是正整数) 求x,y,](/uploads/image/z/3030226-34-6.jpg?t=1.%E5%B7%B2%E7%9F%A5%3Ax%5E2%2Bmx%2Bn%E4%B9%98%E4%BB%A5x%2B2%E5%BE%97%E5%88%B0%E7%9A%84%E7%A7%AF%E4%B8%BAx%5E3%2B2x%2B12%2C%E6%B1%82m%2Cn2.2%5E2009%2A5%5E2011%E7%9A%84%E7%A7%AF%E6%9C%89%E5%A4%9A%E5%B0%91%E4%B8%AA0%3F%E6%98%AF%E5%87%A0%E4%BD%8D%E6%95%B0%3F3.%E6%9C%89%E7%90%86%E6%95%B0x%2Cy%2Cz%E6%BB%A1%E8%B6%B3%EF%BD%9Cx-y-2%EF%BD%9C%2B%EF%BC%883x-6y-7%EF%BC%89%5E2%2B%EF%BD%9C3y%2B3z-4%EF%BD%9C%3D0%2C%E6%B1%82x%5E3n+y%5E3n%2B1+z%5E4n-x%E7%9A%84%E5%80%BC+%EF%BC%88n%E6%98%AF%E6%AD%A3%E6%95%B4%E6%95%B0%EF%BC%89+%E6%B1%82x%2Cy%2C)
1.已知:x^2+mx+n乘以x+2得到的积为x^3+2x+12,求m,n2.2^2009*5^2011的积有多少个0?是几位数?3.有理数x,y,z满足|x-y-2|+(3x-6y-7)^2+|3y+3z-4|=0,求x^3n y^3n+1 z^4n-x的值 (n是正整数) 求x,y,
1.已知:x^2+mx+n乘以x+2得到的积为x^3+2x+12,求m,n
2.2^2009*5^2011的积有多少个0?是几位数?
3.有理数x,y,z满足|x-y-2|+(3x-6y-7)^2+|3y+3z-4|=0,求x^3n y^3n+1 z^4n-x的值 (n是正整数) 求x,y,
1.已知:x^2+mx+n乘以x+2得到的积为x^3+2x+12,求m,n2.2^2009*5^2011的积有多少个0?是几位数?3.有理数x,y,z满足|x-y-2|+(3x-6y-7)^2+|3y+3z-4|=0,求x^3n y^3n+1 z^4n-x的值 (n是正整数) 求x,y,
1.(x^2+mx+n)*(x+2)=x^3+2x^2+mx^2+2mx+nx+2n=x^3+(2+m)x^2+(2m+n)x+12n=x^3+2x+12
2+m=0 2m+n=2 2n=12
m=-2 n=6
2.2^2009*5^2011=10^2009*5^2 有2009个0,2500...000.共2011位数.
3.|x-y-2|+(3x-6y-7)^2+|3y+3z-4|=0
x-y-2=0 3x-6y-7=0 3y+3z-4=0
x=5/3 y=-1/3 z=5/3
剩下就可以自己求了.
1.(x^2+mx+n)*(x+2)=x^3+(m+2)x^2+(2m+n)x+2n=x^3+2x+12
m=-2,n=6
2,2^2009*5^2011=2^2009*5^2009*25=10^2009*25
3,|x-y-2|>=0
(3x-6y-7)^2>=0
|3y+3z-4|>=0
x-y-2=0
3x-6y-7=0
3y+3z-4=0
1 两个想乘得出 x3+mx2+nx+2x2+2mx+2n=x3+2x+13
合并同类项 2+m=0
2n=12
2m+n=2
m=-2, n=6
(x^2+mx+n)X(x+2)=x^3+2x^2+mx^2+2mx+nx+2n=x^3+2x+12
那么,2+m=0,2m+n=2,2n=12
得:n=6,m=-2
第二题是奥数的题吧。
2^2009*5^2011=2^2009*5^2009*25=10^2009*25
是2011位数,共有2009个零。
3,|x-y-2|>=0
(3x-6y-7)^2>=0
|3y+3z-4|>=0
x-y-2=0
3x-6y-7=0
3y+3z-4=0
1. (x^2+mx+n)*(x+2)=x^3+2x+12
x^3+2x^2+mx^2+2mx+nx+2n=x^3+2x+12
x^3+(2+m)x^2+(2m+n)x+2n=x^3+2x+12
(2+m)x^2+(2m+n)x+2n=2x+12
所以2+m=0,2m+n=2,2n=12,解之得m=-2,n=6
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1. (x^2+mx+n)*(x+2)=x^3+2x+12
x^3+2x^2+mx^2+2mx+nx+2n=x^3+2x+12
x^3+(2+m)x^2+(2m+n)x+2n=x^3+2x+12
(2+m)x^2+(2m+n)x+2n=2x+12
所以2+m=0,2m+n=2,2n=12,解之得m=-2,n=6
2. 2^2009*5^2011
=2^2009*5^2009*5^2
=(2*5)^2009*5^2
=10^2009*25
所以2^2009*5^2011的积有2009个0。又由于25是两位数,所以2^2009*5^2011是2011位数。
3.因为|x-y-2|+(3x-6y-7)^2+|3y+3z-4|=0,所以x-y-2=3x-6y-7=3y+3z-4=0
解之得x=5/3 y=-1/3 z=5/3
把x=5/3,y=-1/3,z=5/3代入x^3n y^3n+1 z^4n-x再计算
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