x^2 2 y^2=1PF1 PF2
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![x^2 2 y^2=1PF1 PF2](/uploads/image/f/897392-56-2.jpg?t=x%5E2+2+y%5E2%3D1PF1+PF2)
[(2x+y)^2+(y+2x)(y-2x)-2y(4x-y)]/4y=(4x^2+4xy+y^2+y^2-4x^2-8xy+2y^2)/4y=(-4xy+4y^2)/4y=-x+y=-1/2+1/3
原式=(9x²+24xy+16y²-4x²+y²-5x²+6xy-y²)÷(-2y)=(30xy+16y²)÷(-2y)=-15x
由2(X+Y)3X+3Y=24得:2(X+Y)X+Y=8①;(X+Y/2X)XY/2Y=1得:X+Y=4②;由①、②得出Y=8(1-X),进入②知X=4/7;即Y=24/7
Dx^y+x^-y=2根号2===>(x^y+x^-y)^2=8===>x^2y+x^-2y+2=8===>x^2y+x^-2y=6(x^y-x^-y)^2=x^2y+x^-2y-2=6-2=4==>
原式=(x²-2x+1)+(y²+4y+4)-4=(x-1)²+(y+2)²-4所以最小是0+0-4=-4第二个不对再问:求x,y的值x²+2y
这样算,分离变量:x²+x=(x+1)²-(x+1)然后,除下来,就等于x+1-1=x注意,x≠-1!
3x=8yx/y=8/3(1)x+y/y=x/y+1=8/3+1=11/3(2)2x+3y/x-2y分子分母同时除以y得=(2x/y+3)/(x/y-2)=(16/3+3)/(8/3-2)=(25/3
x(x+y)(x-y)-x(x+y)2=x(x+y)[(x-y)-(x+y)]=x(x+y)(-2y)=-2xy(x+y)=-2×(-1/2)×1=1再问:18p3q3-2pq再答:7(x-1)3-1
1)x(x-y)(x+y)-x(x+y)^2=x((x-y)(x+y)-(x+y)^2)=x(x^2-y^2-x^2-2xy-y^2)=x(-2xy-2y^2)=-2xy(x+y)2)(2a+b)(2
(1)x^2/x)-y-x-y=x-y-x-y=-2y(2)(a/a-b)-(a/a+b)-(2b^2/a^2-b^2)=a(a+b-a+b)/(a^2-b^2)-(2b^2/a^2-b^2)=2b/
解(x-y)(x+y)-(x-2y)²+x(3x-5y)-(x-y)(x-2y)=(x²-y²)-(x²-4xy+4y²)+(3x²-5xy
再答:再答:看后面这个图再答:不懂可以问我
3(x+y)-4(x-y)=4(x+y)/2+(x-y)/6=1令a=x+y,b=x-y3a-4b=4(1)a/2+b/6=1则3a+b=6(2)(2)-(1)5b=2b=2/5a=(6-b)/3=2
4x=9yx=9/4*y(1)(x+y)/y=[(9/4)y+y]/y=(9/4+1)y/y=9/4+1=13/4(2)(y-x)/2x=[y-(9/4)y]/[2*(9/4)y]=(1-9/4)y/
1,-3再问:过程。。。再答:★(x²-2x)+(y²-4y)=5★(x-1)²+(y-2)²=1+4-5★(x-l)²=0,(y-2)²=
∵|x+2y-1|+y²+4y+4=0∴|x+2y-1|+(y+2)²=0∴x=5,y=-2(2x-y)²-2(2x-y)(x+2y)+(x+2y)²=[(2x
x)(-2x-y)-4(x-2y)²]*2y,其
原式=x-x+x-x+……-x+(2-1+4-3+5-4+……+2008-2007-2009)y=0+(1×1004-2009)y=-1005y=1005/2