x的平方加2x减1等于y
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x²+y²-2x+1=0(x-1)²+y²=0所以x-1=0y=0即x=1
x^2+x+y^2-y=X(X+1/X)+Y(Y-1/Y)=2X+Y(Y-1/Y)化不下了希望
原式可以写为(X+Y)的平方减2(X+Y)加1等于0.一目了然,X加Y的值是1.
x²+xy=2xy+y²=-1两式相减得:x²-y²=3两式相加得:x²+2xy+y²=1
x^2-2x+y^2+6y+10=0x^2-2x+1+y^2+6y+9=0(x-1)^2+(y+3)^2=0x-1=0,y+3=0x=1,y=-3(x-y)/(x+y)=4/(-2)=-2
x^2+y^2+2x-4y+5=0,(x+1)^2+(y-2)^2=0,x=-1,y=2(-1)^2006-1/2=1-1/2=1/2
再问:我想要过程耶,,,再答:
x^2+2xy+y^2=25===>(x+y)^2=5^2===>x+y=±5(x-y)^2-3x+3y+2=0===>(x-y)^2-3(x-y)+2=0===>[(x-y)-1]*[(x-y)-2
x的平方加2x加1减y的平方=(x+1)²-y²=(x+y+1)(x-y+1)
再问:你写的字很漂亮再问:已知多项式x减3xym+1加xy减3x减1是五次四项式,单项式3x3ny1-mz与多项式的次数相同,求m,n的值。再问:这题你懂做吗?再问:错了错了,我题目抄错了
由题得X=2YX+Y-3=0Y=1X=2x的y加1乘方=4
x²-4y²+2x-4y=(x+2y)(x-2y)+2(x-2y)=(x-2y)(x+2y+2)
x-y=-1(x+y)^2+2(x+3y)=7这个没错吧再问:是的再答:再答:
x^2+4x+y^2-2y+5=0(x^2+4x+4)+(y^2-2y+1)=0(x+2)^2+(y-1)^2=0x=-2,y=1x^2+y^2=(-2)^2+1^2=4+1=5
3∵x/y=1/2∴y=2x故(x^2+2xy+y^2)/(x^2-xy+y^2)=(x+y)^2/(x^2-xy+y^2)=(x+2x)^2/(x^2-x·2x+4x^2)=9x^2/(3x^2)=
xy=0.5×【(x-y)-x-y】=1-9=-8
x^2-y^2=(x+y)*(x-y)=-1*(-3)=3
x²+y²=x²-xy+y²+xy=3+5=82x²+xy+3y²=2x²-2xy+3y²+3xy=2(x²-
如果x的平方加xy等于2,y的平方加x的y等于-1,则x的平方-y的平方=?x的平方加2xy加y的平方等于多少?x²+xy=2y²+xy=-1x²+xy-y²-
x+y=2x^2-y^2+4y=(x+y)(x-y)+4y=2x-2y+4y=2x+2y=2(x+y)=4