作业帮已知:3m n=4x
来源：学生作业帮助网 编辑：作业帮 时间：2024/04/29 05:23:34
m+n=2mn=-42（mn-3m）-3(2n-mn)=2mn-6m-6n+3mn=5mn-6(m+n)=-20-12=-32
∵M、N都是单项式∴3xM也是单项式∵3xM-15x^2=6x^2y^2+N又∵-15x^2≠6x^2y^2∴3xM=6x^2y^2,N=-15x^2
m+n=3-2kmn=k^23-2k=k^2得到k=1或-3所求=mn(m+n-1)=0或72
(2mn+2m+3n)-(3mn+2n-2m)-(m+4n+mn)先去括号=2mn+2m+3n-3mn-2n+2m-m-4n-mn合并同类项=-2mn+3m-3n=-2mn+3(m-n)把m-n=2,
解（-2mn+2m+3n)-(3mn+2n-2m)-(m+4n+mn）=-2mn+2m+3n-3mn-2n+2m-m-4n-mn=-2mn-3mn-mn+2m+2m-m+3n-2n-4n=-6mn+3
3x(M-5x)=3xM-15x²=6x²y³+n3xM=6x²y³-15x²=NM=2xy³MN=-30x³y
有实根,则△≥04(m+1)²-4(3m²+4mn+4n²+2)≥0m²+2m+1-3m²-4mn-4n²-2≥02m²+4mn+
由题知道△≥0化简为(m-1)^2+(m+2n)^2=0最后得出M=1N=-1/2所以mn=-1/2
函数图象与y轴交点在x轴下方∴3-n3且m不等于-2函数图像过原点3-n=0且2m+4不等于0∴n=3且m不等于-2
2x（M+3x）=6x²y²+N2Mx+6x²=6x²y²+N∴2Mx=6x²y²N=6x²即：M=3xy²N
2x(M+3x)=6x²y²+N2xM+6x²=6x²y²+N由于6x²=6x²y²不恒等,根据对应项相等,得2xM=6
设N(-a^2/4,a)线段MN中点(x,y)x=(3-a^2/4)/2y=(a+1)/2消去a(y-1/2)^2=-2x+3
m（a-3,4）n（-5,3+2b）mn=（a+2,1-2b）直线mn平行于x轴故1-2b=0b=0.5而mn=3故a+2=3或-3所以a=1或-5
64=MQ=1/2MP=1/2*4/3MNSOMN=4*2/1*3/4=6
-MN(M^2N^5-MN^3-N)=-（-6)^3+(-6)^2-(-6)=258
-2mn+2m+3n-3mn-2n+2m-4n-m-mn=-6mn+3m-3n=-6mn+3(m-n)=6+9=15
原式=-2mn+2m+3n-3mn-2n+2n-m-4n-mn=-6mn+m-n=-6×2+4=-8
1、减去-2x+3x²等于-3-5x+4x²的代数式=-3-5x+4x²+(-2x+3x²)=7x²-7x-32、M+N=-2,是不是m+n=-2?2
(-m-4n-mn)-(2mn-2m-3n)-(3mn+2n-2m)=-m-4n-mn-2mn+2m+3n-3mn-2n+2m=3m-3n-6mn=3(m-n)-6mn=3×3-6×(-3)=9+18
2（mn-3m)-3（2n-mn）=2mn-6m-6n+3mn=2mn+3mn-6(m+n)=32