方程组2x-y=6 (3 2y)(4x-2y)=192
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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*
设(x+y)为t,(x-y)为p,所求的解为c所以t/2+p/2=64t-5p=c整理得:5t+5p=604t-5p=c两式相加得9t=60+cc=9t-60所以4(x+y)-5(x-y)=9(x+y
(用换元法)设A=x+y,B=x-y原方程组可化为2A-3B=1,6A+7B=51解得A=5,B=3即x+y=5,x-y=3解得x=4,y=1
x+y/3+x-y/2=63(x+y)-2(x-y)=282x+2y+3x-3y=363x+3y-2x+2y=285x-y=36x+5y=285x-y=365x+25y=14026y=104y=4x=
解析:令x+y=m,x-y=n,那么原方程组可化为:{2分之m+3分之n=6(1){2m+n=12(2)(1)×6可得:3m+2n=36(3)(2)×2可得:4m+2n=24(4)(4)-(3)可得:
2x+y=6x+2y=9相加得3x+3y=15x+y=5相减得2x+y-x-2y=6-9x-y=-3
x+y/3+x-y/2=6为①式3(x+y)-2(x-y)=28为②式将①乘以6得6x+2y=6x-3y=36化简得12x-y=36化简②得x+5y=28得x=28-5y带入上式则12(28-5y)-
{5(x+y)+3(x-y)=2{7(x+y)-3(x-y)=-6原方程组化简得﹛4x+y=1(1)2x+5y=-3(2)(1)×5得20x+5y=5(3)(3)-(2)得18x=8x=4/9代入(1
原方程组变形得:①3﹙x+y﹚-﹙x-y﹚=4②3﹙x+y﹚+﹙x-y﹚=6∴①+②得:③x+y=10/3②-①得:④x-y=1∴③+④得:x=13/6③-④得:y=7/6∴x=13/6,y=7/6.
合并方程组:x+y/2=3x-2y;3x-2y=10+6x+y/4;得出:x=5y/4;从而算出:x=-25/12,y=-5/3.手机打很累.
{{x-y)/3-(x+y)/4=2①{(x-y)/6-(x+y)/8=3②②×2得:(x-y)/3-(x+y)/4=6③①与③矛盾∴原方程组无解
(x+y)/2+(x-y)/3=6①5(x+y)-2(x-y)=4②由①得3x+3y+2x-2y=365x+y=36y=36-5x③由②得5x+5y-2x+2y=43x+7y=4④③代入④得3x+25
2(x-y)/3-x+y/4=-1(1)6(x+y)-4(2x-y)=16(2)(1)方程两边同乘以12得8(x-y)-3(x+y)=-12合并同类项得5x-11y+12=0(3)(2)合并同类项得1
先将第一个等式整理得12X+Y=36,第二个等式整理得-X+9Y=2,由第一个等式得Y=36-12X,通过换元法得-X+9(36-12X)=2,解出X=322/109,再把X=322/109代入-X+
∵3/x+y+2/x-y=6∴x+5y=28∵3(x+y)-2(x-y)=28∴x=5/6∴y=163/30
若3x>y则方程互相矛盾,所以3x<>y,解得x=9/10,y=21/5
X=1,Y=4X+Y=5X-Y=-3
{2x+y=6①{x-3y=1②①减②得x+4y=57y(x-3y)²-(3y-x)³=7y(x-3y)²+(x-3y)³=7y(x-3y)²+(x-
解方程X=(6+M)/3Y=2M/3-2因为x>0y-6m
7Y(X-3Y)^2-(3Y-X)^3=7Y(X-3Y)^2+(X-3Y)^3=(X-3Y)^2(7Y+X-3y)=(X-3Y)^2(X+4Y)因为X-3Y=1所以上式=(X-3Y)^2(X+4Y+X