4x-3y=14,5x 4y=2
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1,x+y/2+x-y/3=6即:5x-y=36①4(x+y)-5(x-y)=2即:-x+9y=2②①+②*5==可接2,先化整:3(x+y)+2(x-y)=36①4(x+y)-5(x-y)=2②①*
多项式3x2-34x4y-1.3+2xy2有4项组成,最高项是-34x4y,次数是5,常数项是-1.3.∴(1)四项式;(2)3x2,-34x4y,-1.3,2xy2;(3)-34x4y;(4)5次;
令a=x+2yb=3x-ya/2+b/3=5(1)0.2a+0.8b=4(2)所以a=20-4b代入(1)10-2b+b/3=55b/3=5b=3a=20-4b=8所以x+2y=8(3)3x-y=3(
原式=(9x²+24xy+16y²-4x²+y²-5x²+6xy-y²)÷(-2y)=(30xy+16y²)÷(-2y)=-15x
(4x-2y-z)-{5x[8y-2y-(x+y)]-x+(3y-10z)]=4x-2y-z-5x[6y-(x+y)]+x-(3y-10z)=4x-2y-z-30xy+5x²+5xy+x-3
我怕来不及,等等发给你!再问:慢慢来,,,,,,再问:还没好??
设x-y=mx+y=n则6m-2n=143m+n=5解得m=2n=-1即x-y=2x+y=-1解得x=1/2y=-3/2
x+2y=-5&2x-5y=-1由2式得:x=1/2×(5y-1);代入1式得:1/2×(5y-1)+2y=-5;y=-9/13;再代入1式得x+2×(-9/13)=-5得:x=-3×8/13
多项式2x3y2-3x2y3-5x4y+6xy4-5中,x的系数依次3,2,4,1,按x的降幂排列是-5x4y+2x3y2-3x2y3+6xy4-5.
3x+3y+2x-2y=36①4x+4y-5x+5y=2②(3x+2x)+(3y-2y)=365x+y=36y=36-5x③把③带入②得,-x+9(36-5x)=2x=7把x=7带入③得y=1∴此方程
化简得:-x+7y=11①7x+3y=27②①式×7得:-7x+49y=77③②+③得:52y=104∴y=2代入①得:x=3∴x=3,y=2再问:亲,是代入法哦!再答:代入法①式得3x+3y-4x+
楼上的全错,{(3x+y)(3x-y)-(x-5y)(5x-y)-(x-2y)²}÷(-4x)={9X²-(5x²-xy-25x²+5y²)-(x&s
因为(x-y)/(x+y)=3,则(x+y)/(x-y)=1/3则5(x-y)(x+y)-(x+y)/2(x-y)=5*3-1/(3*2)=15-1/6=89/6
3x+4y=x+2y+62x-x+4y-2y=62x+2y=6x+y=6/2x+y=3
条件不完全.补充后给你解答.4x-5y是4x=5y还是缺少了等号后的值?再问:4x-5y=3再答:
解(x-y)(x+y)-(x-2y)²+x(3x-5y)-(x-y)(x-2y)=(x²-y²)-(x²-4xy+4y²)+(3x²-5xy
题意不清什么是平方,*吗?那么**代表三次方还是4次方呢
1、3x-2y=32x+2y=176x-4y=66x+6y=5110y=45y=4.5x=42方程无解3、x+3y=62x-3y=32x+6y=122x-3y=3y=1x=34、2x+3y=11y-2
∵-2x3m+1y2n•4xn-6y-3-m=-8x3m+n-5y2n-3-m,又∵-2x3m+1y2n与4xn-6y-3-m的积与-4x4y是同类项,∴3m+n−5=42n−3−m=1,解得:m=2
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