3X+10Y=14 10X+15Y=32
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10/(x+y)+3/(x-y)=-5.(1)15/(x+y)-2/(x-y)=-1.(2)(1)×3-(2)×2得:(9+4)/(x-y)=-13x-y=-1.(4)(1)×2+(2)×3得:(20
(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
(x+y)/6+(x-y)/10=3①(x+y)/6+(y-x)/10=-1②①可变为:(x+y)/6-(y-x)/10=3③②+③=(x+y)/3=2得x+y=6④②-③=(y-x)/5=-4得y-
设a=(x-1)(x-2)(x-3)(x-4)(x-5)(x-6)(x-7)(x-8)(x-9)那么y=a*(x-10);那么y^=a^*(x-10)+a*(x-10)^=a^*(x-10)+a那么y
2x+3y=103x+2y=15,把两式相加得:5x+5y=25,x+y=5,把两式相减得:-x+y=-5,x-y=5,(x+y)(x-y)=5×5=25
-3(2x-y)-{7x-[6x+2y-(10x-8y)]-x-2(3x-4y)}=-6x+3y-7x+(6x+2y-10x+8y)+x+6x-8y=-13x+3y-4x+10y+7x-8y=-10x
﹛(x+y)分之10+(x-y)分之3=-5﹛(x+y)分之15-(x-y)分之2=-1设(x+y)=ax-y=b则:10/a+3/b=-5①15/a-2/b=-1②①×2+②×3得:20/a+45/
1、2X-3Y=101)-4X+Y=52)1)×2+2)得4X-6Y-4X+Y=20+5-5Y=25Y=-5把Y=-5代入2)中,得-4X-5=5X=-5/2解得X=-5/2,Y=-52、3X-2Y=
X+Y分之X-Y等于3x=-2yX+Y分之2(x-y)减X+Y分之3X+Y=(-x-3y)/(x+y)=1
.死算呗xy-2x+3y-6=xy+10x-3y-30,2x-y=4xy+3x+y+3=xy+12x-2y-24,3x-y=92式减1式,x=5,y=6
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
化简x+y=105x+7y=625x+5y+2y=622y=62-50y=6x=4
①-②可得:x-y/10-y-x/10=4x-y/5=4x-y=20——③①+②可得:x+y/3=2x+y=6——④由③④可得:x=13,y=-7
5(x+y)-2x=03x+5y=06x+10y=0①3x-10(x+y)=27x+10y=-2②②-①x=-2代入①y=6/5
方程组整理得:2(x+y)-3(x-y)=3①4(x+y)+3(x-y)=15②①+②得x+y=3③,把③代入①,得x-y=1④,③+④得:x=2,③-④得:y=1,则原方程组的解是x=2y=1.
x2-3x=1x2-6x=-5x2-6x9=-59(x-3)=4x-3=±2x1=1x2=5y23y-2=0y23y2.25=22.25(y1.5)=4.再问:我不明白呀3X+7Y=152X-5Y=-
-3(2x-y)-{7x-〔6x+2y-(10x-8y)〕-x-2(3x-4y)}=-6x+3y-{7x-6x-2y+10x-8y-x-6x+8y}=-6x+3y-(4x-2y)=-10x+5y由(x
这慢慢做不就好了,这么简单的式子
什么意思?再问:tangram_guid_1358503626031再答:1:2x+3y=7,3x-5y=1;x=2y=12:3x+5y=5,3x-4y=23;x=5y=-23:3x+5y=5,3x-