几道数学题.会多少做多少吧 有点难.1.m^2+m-1=0,求m^3+2m^2+2011的值2.a-b=5,ab=6,求(a+b)^23.已知a+b=m,ab=-4,化简(a-2)(b-2)的结果为?4.若x^2+x+1/4=(x-k)^2,则k=5.若x-y=4,x^2-y^2=8,则y-x=
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![几道数学题.会多少做多少吧 有点难.1.m^2+m-1=0,求m^3+2m^2+2011的值2.a-b=5,ab=6,求(a+b)^23.已知a+b=m,ab=-4,化简(a-2)(b-2)的结果为?4.若x^2+x+1/4=(x-k)^2,则k=5.若x-y=4,x^2-y^2=8,则y-x=](/uploads/image/z/1721134-46-4.jpg?t=%E5%87%A0%E9%81%93%E6%95%B0%E5%AD%A6%E9%A2%98.%E4%BC%9A%E5%A4%9A%E5%B0%91%E5%81%9A%E5%A4%9A%E5%B0%91%E5%90%A7+%E6%9C%89%E7%82%B9%E9%9A%BE.1.m%5E2%2Bm-1%3D0%2C%E6%B1%82m%5E3%2B2m%5E2%2B2011%E7%9A%84%E5%80%BC2.a-b%3D5%2Cab%3D6%2C%E6%B1%82%EF%BC%88a%2Bb%29%5E23.%E5%B7%B2%E7%9F%A5a%2Bb%3Dm%2Cab%3D-4%2C%E5%8C%96%E7%AE%80%EF%BC%88a-2%EF%BC%89%EF%BC%88b-2%EF%BC%89%E7%9A%84%E7%BB%93%E6%9E%9C%E4%B8%BA%3F4.%E8%8B%A5x%5E2%2Bx%2B1%2F4%3D%28x-k%29%5E2%2C%E5%88%99k%3D5.%E8%8B%A5x-y%3D4%2Cx%5E2-y%5E2%3D8%2C%E5%88%99y-x%3D)
几道数学题.会多少做多少吧 有点难.1.m^2+m-1=0,求m^3+2m^2+2011的值2.a-b=5,ab=6,求(a+b)^23.已知a+b=m,ab=-4,化简(a-2)(b-2)的结果为?4.若x^2+x+1/4=(x-k)^2,则k=5.若x-y=4,x^2-y^2=8,则y-x=
几道数学题.会多少做多少吧 有点难.
1.m^2+m-1=0,求m^3+2m^2+2011的值
2.a-b=5,ab=6,求(a+b)^2
3.已知a+b=m,ab=-4,化简(a-2)(b-2)的结果为?
4.若x^2+x+1/4=(x-k)^2,则k=
5.若x-y=4,x^2-y^2=8,则y-x=
几道数学题.会多少做多少吧 有点难.1.m^2+m-1=0,求m^3+2m^2+2011的值2.a-b=5,ab=6,求(a+b)^23.已知a+b=m,ab=-4,化简(a-2)(b-2)的结果为?4.若x^2+x+1/4=(x-k)^2,则k=5.若x-y=4,x^2-y^2=8,则y-x=
1.根据题目m^2+m=1
m^3+2m^2+2011=m^3+m^2-m+m^2+m+2011=m(m^2+m-1)+(m^2+m)+2011=0+1+2011=2012
2.(a+b)^2=(a-b)^2+4ab=5^2+4*6=49
3.(a-2)(b-2)=ab-2(a+b)+4=-4-2m+4=-2m
4.(x-k)^2=x^2+k^2-2xk=x^2+x+1/4
所以-2xk=x; k^2=1/4 所以k=1/2
5.x^2-y^2=(x+y)(x-y)=8 因为x-y=4 所以x+y=2 x=3,y=-1 所以y-x=-4