作业帮x y=5,x-y 2z=5,x 3y-z=3,mx-2y z=0则m=_
来源：学生作业帮助网 编辑：作业帮 时间：2024/04/29 12:34:53
x3+y3-x2y-xy2=(x+y)(x2-xy+y2)-xy(x+y)=（x+y)(x2-2xy+y2）=（x+y)（x2+2xy+y2-4xy）=（x+y）[(x+y)2-4xy]=10×（10
∵x+y=1，∴x3+y3+3xy=（x+y）（x2-xy+y2）+3xy=x2+y2+2xy=（x+y）2=1．
x³+2y+√5*y=17-5√5xy是有理数则,x³+2y=17√5*y=-5√5解得,x=3,y=-5√2(x-y)=√2(3+5)=8√2如果x,y也在根号下,则√[2(x-
x3+3xy+y3=（x+y）（x2-xy+y2）+3xy，=（x2-xy+y2）+3xy，=（x+y）2-3xy+3xy，=1．
x3次方y-2x2y2+xy3=xy(x²-2xy+y²)=xy（x-y）²=3x3²=27如果本题有什么不明白可以追问,再问：=xy(x2-2xy+y2)=x
f'x=3x^2+3y=0-->y=-x^2f'y=-3y^2+3x=0-->y^2=xx=y^2=x^4-->x=0,1,-->y=0,-1f"xx=6x,f"yy=-6y,f"xy=3f(0,0)
5x3次方y*（-3y）²-6x²y²*（-xy）=5x^3*y*9y^2+6x^3y^3=45x^3y^3+6x^3y^3=51x^3y^3不懂可追问,有帮助请采纳,谢
3与（9-x）之间是乘号吗.若是则解为x=4.若不为乘号则5x+27x-3x2=35.-3x2+32x-35=0.则解为x=16+根号1511/3.或x=16-根号151/3
(x+y)^3=X^3+3X^2Y+3XY^2+Y^3x^2y+xy^2=303x^2y+3xy^2=90x^3+Y^3=35
因为x3+3x+5=7,x3+3x=23x3+9x-2=3(x3+3x)-2=3*2-2=4
f'x=3x^2-3yf'y=3y^2-3xf'x=0,f'y=0即x^2-y=0y^2-x=0消去yx^4-x=0即x(x-1)(x^2+x+1)=0x=0或1y=0或1x=y=0时f(x,y)=0
求偏导另其等于0即可
x^3+y^3+x^3y^3=12,x^3+y^3+x^3y^3+1=13,（x^3+1)(y^3+1)=13(x+1)(x^2-x+1)(y+1)(y^2-y+1)=13;x+y+xy=0,x+y+
迷惑人?70/3
这是要立方和公式,x^3+y^3+3xy=(x+y)(x^2-xy+y^2)+3xy=x^2-xy+y^2+3xy=(x+y)^2=1
5开四次根号再问：详细步骤，谢谢再答：X4+5*3+5*2+5*-6=0X4+15+10-30=0X4-5=0X4=5X=5开四次根号
因为(x^3)^5=a^15b^15所以x^15=(ab)^15所以x=ab祝学习愉快!
5x-(120-x)x3.75=162.55x-450+3.75x=162.58.75x=612.5x=70
左边=x3-x2y+xy2+x2y-xy2+y3=x3+y3=右边