0那么x y等于多少
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![0那么x y等于多少](/uploads/image/f/35923-67-3.jpg?t=0%E9%82%A3%E4%B9%88x+y%E7%AD%89%E4%BA%8E%E5%A4%9A%E5%B0%91)
原式=xy(y^4-1)=xy(x²+1)(x²-1)=xy(x²+1)(x+1)(x-1)
x分之x的绝对值加y分之y的绝对值等于0所以x与y异号,即xy再问:没听懂再答:1.x0x分之x的绝对值加y分之y的绝对值=-1+1=02.x>0,y
x²-5xy+6y²=0,(x-3y)(x-2y)=0x=3y或x=2y(1)当x=3yx+y分之x-y=(3y-y)/(3y+y)=1/2(2)当x=2yx+y分之x-y=(2y
y²=12y=±√12=±2√3xy=√6×(±2√3)=±2√18=±6√2于是4/xy=4/(±6√2)=±√2/3再问:你4/(±6√2)那里是怎么化简的,可以写下过程吗。。再答:4/
x+y=2,y=2-x,xy=x(2-x)若x=0,2,xy=0若2>x>0,2>xy>0x2,xy
x^2+2xy+y^2=(x^2+xy)+(xy+y^2)=2+7=9再问:不等式4x减3小于2x加5的解集是多少?
x+y=3-------(1)xy=1--------(2)将(1)平方得x^2+y^2+2xy=9------(3)将(2)乘以2得2xy=2--------(4)将(3)减去(4)得x的平方加上y
x²+xy=3………………………①y²+xy=-2……………………②①+②得:x²+2xy+y²=1(x+y)²=1x+y=±1∴x²+3x
(xy)的平方+24xy+80=0(这里24前面少了符号,暂且用+)(xy+20)(xy+4)=0xy=-20xy=-4
你先设x/y=k,即x=yk所以原式=3k^2y^2+ky^2-4y^2=0即y^2(3k^2+k-4)=0因为y不能等于0,所以^2不等于0即3k^2+k-4=0得k=1(x不等于y,舍去),K=-
2(x+xy)-[(xy-3y)-x]-(-xy)=2x+2xy-xy+3y+x+xy=3x+3y+2xy=3(x+y)+2xy=3*(-2)+2*3=0
前面,22,后面8再问:有再问:过程吗?再答:
1/x-1/y=2(y-x)/xy=2y-x=2xy(3x+5xy-3y)/(x-xy-y)=[5xy-3(y-x)]/[-xy-(y-x)]=(5xy-6xy)/(-xy-2xy)=-xy/-3xy
x^2+2xy+y^2=(x^2+xy)+(xy+y^2)=2+7=9
XY的相反数
得0=(-X+X)y=0×y=0
2A-3B=2(3x²-xy+y²)-3(2x²-3xy-2y²)=6x²-2xy+2y²-6x²+9xy+6y²=7x
2再问:过程再答:一个数除以本身等于1再答:因为非0,绝对值说明为正